Step One:
As with any work it is proper to begin with a purification. Begin by taking a ritual bath. While still in the bath say the following:

Preliminary Purification Invocation

Bright One of the Heavens, wise ISHTAR
Mistress of the Gods, whose "yes" is truly "yes"
Proud One among the Gods, whose command is supreme
Mistress of Heaven and of Earth, who rules in all places
ISHTAR, at your Name all heads are bowed down
I . . . son of . . . have bowed down before you
May my body be purified like lapis lazuli!
May my face be bright like alabaster!
Like shining silver and reddish gold may I not be dull!

After you have said the words fully submerse yourself in the water and wash yourself clean. Drain the water and remove yourself from the bath. Dress in your ritual clothes as well as your consecrated frontlet of calling and silver amulet of protection around your right wrist.

Step Two:
Now that you have purified your body you must purify your space. Go to the area of your working. You should have already drawn and set up your double circle, mandala, and seals, facing north say the following purification spell:

ENU SHUB
AM GIG ABSU
KISH EGIGGA
GAR SHAG DA SISIE AMARDA YA
DINGIR UD KALAMA SINIKU
DINGIR NINAB GUYU NEXRRANIKU
GA YA SHU SHAGMUKU TU!

Now scatter salt sixty times about your circle. I prefer sea salt but it does not matter.

Step Three:
Now that you are pure in body and space the book says it is time to call upon your personal gods. This is interesting to me since it does not say to call upon the Sumer/Babylonian gods the Necronomicon covers. I take this opportunity to include contemporary ceremonial rituals at this time.

I pray for protection then perform Lesser Banishing Ritual of the Pentagram, the Lesser Banishing Ritual of the Hexagram, followed by some sort of invocation, either the Bornless one or a similar hermetic one.

Step Four:
Now that you are fully prepared it is time to open the quarter gates. Stand facing north with your arms out and legs apart forming the shape of the ARRA sign to remind the gods of the covenant which by that right you can call open the gates.

Say the following:

Invocation of the North Gate

Thee I invoke, Silver Hunter from the SacredCity of UR!
Thee I call forth to guard this North Place of the Most Holy Mandal against the vicious warriors of Flame from the Principalities of DRA!
Be thou most vigilant against the UTUKKI of TIAMAT
The Oppressors of ISHNIGARRAB
The Throne of AZAG-THOTH!
Draw Thy bow before the fiends of ABSU
Loose Thy arrow at the hordes of Dark Angels that beset the beloved of ARRA on all sides and in all places.
Be watchful, Lord of the North Ways.
Remember us, King of our Homeland, Victor of Every War and Conqueror over Every Adversary.
See our Lights and hear our Heralds, and do not forsake us.
Spirit of the North, Remember!

While still in the body form of the ARRA sign and still facing north say the following:

Invocation of the Eastern Gate

Thee I invoke, Mistress of the Rising Star.
Queen of Magick, of the Mountains of MASHU!
Thee I call forth this day to guard this Most Holy mandal against the Seven Ensnarers, the Seven Liers-In-Wait, he evil Maskim, the Evil Lords!
Thee I Summon, Queen of the Eastern Ways, that thou mayest protect me from the Eye of Death, and the evil rays of the ENDUKUGGA and NINDUKUGGA!
Be watchful, Queen of the Eastern Ways, and Remember!
Spirit of the East, Remember!

While still in the body form of the ARRA sign and still facing north say the following:

Invocation of the Southern Gate

Thee I invoke, Angel, Guardian against the URULUDreadCity of Death, Gate of No Return!
Do Thou stand at my side!
In the Names of the most Mighty Hosts of MARDUK and ENKI, Lords of the Elder Race, the ARRA, do Thou stand firm behind me!
Against PAZUZU and HUMWAVA, Fiends of the Southwest Winds, do Thou stand form!
Against the Lords of the Abominations, do Thou stand form!
Be Thou the Eyes behind me,
The Sword behind me,
The Spear behind me,
The Armour behind me.
Be watchful, Spirit of the Southern Ways, and Remember!
Spirit of the South, Remember!

While still in the body form of the ARRA sign and still facing north say the following:

The Invocation of the Western Gate

Thee I invoke, Spirit of the Land of MER MARTU!
Thee I invoke, Angel of the Sunset!
From the Unknown God, protect me!
From the Unknown Demon, protect me!
From the Unknown Enemy, protect me!
From the Unknown Sorcery, protect me!
From the Waters of KUTULU, protect me!
From the Wrath of ERESHKIGAL, protect me!
From the Swords of KINGU, protect me!
From the Baneful Look, the Baneful Word, the Baneful Name, the Baneful Number, the Baneful Shape, protect me!
Be watchful, Spirit of the Western Ways, and Remember!
Spirit of the West Gate, Remember!

Now that you have called upon the four quarter gates it is now time to unite them together and fully open them. While still in the body form of the ARRA sign and still facing north say the following:

The Invocation of the Four Gates

MER SIDI!
MER KURRA!
MER URULU!
MER MARTU!
ZI DINGIR ANNA KANPA!
ZI DINGIR KIA KANPA!
UTUK XUL, TA ARDATA!
KUTULU, TA ATTALAKLA!
AZAG-THOTH, TA KALLA!
IA ANU! IA ENLIL! IA NNGI!
ZABAO!

Sit down in your mandala and experience the power of the open gates.

Step Five:
Now before you can safely call the fire god you must show subservience to Enki. The book makes reference to a modified line from the Chaldean oracles. You could make the argument that this is a hidden reference to consecrate by fire and water but since you have already purified your body and your space and the fact the book makes no other reference to this I take it at face value.

Sprinkle salt water within your circle and repeat the following:
Therefore the priest who governeth the works of fire, and god fire, Gishbar called Gibil, must firstly sprinkle with the water of the seas of Enki.

Step Six:
It is now time to call upon the fire god. Repeat the following incantation:

THE CONJURATION OF THE FIRE GOD

Spirit of the Fire, Remember!
GIBIL, Spirit of the Fire, Remember!
GIRRA, Spirit of the Flames, Remember!
O God of Fire, Mighty Son of ANU, Most terrifying among Thy Brothers, Rise!
O God of the Furnace, God of Destruction, Remember!
Rise Up, O God of Fire, GIBIL in Thy Majesty, and devour my enemies!
Rise up, O God of Fire, GIRRA in Thy Power, and burn the sorcerers who persecute me!
GIBIL GASHRU UMANA YANDURU
TUSHTE YESH SHIR ILLANI U MA YALKI!
GISHBAR IA ZI IA
IA ZI DINGIR GIRRA KANPA!
Rise up, Son of the Flaming Disk of ANU!
Rise up, Offspring of the Golden Weapon of MARDUK!
It is not I , but ENKI, Master of the Magicians, who summons Thee!
It is not I, but MARDUK, Slayer of the Serpent, who calls Thee here now!
Burn the Evil and the Evildoer!
Burn the Sorcerer and the Sorceress!
Singe them! Burn them! Destroy them!
Consume their powers!
Carry them away!
Rise up, GISHBAR BA GIBBIL BA GIRRA ZI AGA KANPA!
Spirit of the God of Fire, Thou art Conjured!
KAKKAMMANUNU!

Immediately following you should light the prepared bowl with the signs and pine chips inside the double circle. Toss in the sacrifice to the watcher. Also light any incense you have at this time.

Step Seven:
Now is when things will start to get hairy. It is time to summon the watcher. Recite the following conjuration:

IA MASS SSARATU!
I conjure Thee by the Fire of GIRRA
The Veils of Sunken Varloorni,
And by the Lights of SHAMMASH.
I call Thee here, before me, in visible shadow
In beholdable Form, to Watch and Protect this Sacred Circle, this Holy Gate of (N.)
May He of the Name Unspeakable, the Number Unknowable,
Whom no man hath seen at any time,
Whom no geometer measureth,
Whom no wizard hath ever called
CALL THEE HERE NOW!
Rise up, by ANU I summon Thee!
Rise up, by ENLIL I summon Thee!
Rise up, by ENKI I summon Thee!
Cease to be the Sleeper of EGURRA.
Cease to lie unwaking beneath the Mountains of KUR.
Rise up, from the pits of ancient holocausts!
Rise up, from the old Abyss of NARR MARRATU!
Come, by ANU!
Come, by ENLIL!
Come, by ENKI!
In the Name of the Covenant, Come and Rise up before me!
IA MASS SSARATU! IA MASS SSARATU! IA MASS SSARATU ZI KIA KANPA!
BARRGOLOMOLONETH KIA!
SHTAH!

At the words IA MASS SSARATU thrust your sword into the ground inside your circle but in front of the AGA MASS SSARATU. Note I am talking about the sword of the watcher NOT the copper dagger of Inanna.

Greet the watcher and tell him what your intentions for this ritual is, instruct him in his duties. If you have given him his sacrifice and done everything up to this point correctly he will obey.

NOTE: This should go without saying but while the watcher is present, Do NOT leave the circle at any time for any reason!

Step Eight:
Now is the time to perform your working regardless if it is a spell or an evocation of one of the fifty names.


Step Nine:
Release the spirit if you performed an evocation.

Thank the watcher and release him by placing your left hand upon the sword and saying the following:
BARRA MASS SSARATU! BARRA!
Pull the sword from the ground.

Thank the fire god and release him.

Stand in the ARRA sign and close each quarter gate.

Perform the Banishing Crown of Anu, the Lesser Banishing Ritual of the Hexagram, and the Lesser Banishing Ritual of the Pentagram.

Pray and say thank you for a safe and successful working.

Finished.