In addition to Cliff's th350 book, I've found this th350 rebuild book by Ron Sessions was invaluable. It has great detail on the interchangeability of parts if you are swapping parts from one th350 to another. There are some differences with internal parts from early years to later years. I was using the best parts from several parts transmissions from different years, and could not have done it without this book. I don't know of another source for this valuable interchange info.
https://www.amazon.com/Turbo-Hydra-M.../dp/0895860511
And I bought a th350 rebuild video off of eBay that was helpful too, since it helps to follow along as somebody else does it. It didn't have the interchange info, but a basic take apart, inspection of condition of parts, and put back the same parts replacing wear items like new clutches, seals, etc. It's much easier if you're able to re-use all the hard parts from the original trans that you're working on, and not mixing and matching.
I also referred to the factory service manual a few times, just to double-check some things. With all these references, you'd have all the info necessary to do it. Add a few special tools, and you can do it.