http://www.spiritreleasement.org/intro/soulintro.htmlI only took the top link off a google search as it seemed relevant. I'd suggest you look further into the subject yourself.
Ultimately I think in order to have a successful soul recovery you'd need to have at least the assistance of a real shaman. Ideally the shaman would do the soul recovery him/her self. Soul recovery essentially requires one to venture into the spirit world and attempt to coerce the soul back to the sick person where the shaman would then "mend" the soul back in place where it will merge and heal with the person. After such a ritual the person will then spend a period of time away like on a vacation or secluded in a peaceful environment to fully recover and make sure their soul fragment does not reject the host. This would also require the presance of someone at least able to guide an individual through the process.
I would very suggest you do not attempt to do a soul recovery ritual yourself. If the fragment rejects you it might be lost for good or may never be willing to return. Again I stress the importance of avoiding ritual magick all together and stick to conventional medicine. Then sometimes conventional medicine isn't enough. And if that has failed then I wish the best of luck.
Another suggestion I'd is looking into eastern philosophy and medicine, particularly meditation. So browse the eastern traditions section of this site or search web. If you have a lybrary near by, unless its in the deep back woods of Alabama, will likely have books or access to books on Eastern philosophy. I think eastern philosophy has a more grounded approach towards the human mind, imho.