Its very straight forward. I have done it and am currently working on a push button 727. My advice, buy the below linked book. Follow it and you'll be just fine. Hardest part for me is the snap ring that holds the tail shaft on.
Chrysler TorqueFlite A-904 & A-727 Transmissions: How to Rebuild (Workbench How-to) by Hand, Tom: CarTech 9781613253359 Paperback - Buyback Express
This one is also nice to have
https://www.amazon.com/dp/1557883998/?tag=joeychgo-20
