The reason I have never touched the innards of a TorqueFlite is because every operation seems to call for a special tool "this" and a special tool "that". At least that's how it was when I was contemplating a GM AT rebuild years ago (mini-blazer).
You really don't need much, and can make some of them, including using "what you have" for some. This guy gets a bit tedious, but there are some ideas in here about home made/ budget tools
This second video will likely cover what you are referring to
