but the real special thing was the experience. The ability to see a thrust washer and know it was worn and wouldn't work, or the proper way to install a quad ring and know you hadn't pinched it.
Stuart is absolutely correct about having experience.
A few years back, I rebuilt a C4 auto as part of my ongoing restoration of my '65 Mustang 2+2 fastback. The rebuild was a success, I think. (car still hasn't been driven except up & down the driveway). After I got into it I quickly realized I couldn't tell what was acceptable wear on a few parts. And the rebuild kit didn't come with all the parts that could possibly be worn, such as that aformentioned thust washer.
I had fun doing it, but I am fully aware of the possibility of transmission failure.
So if you want to do it for fun and are ready to accept the possible bad outcome, I say go for it. You'll be proud as a peacock when the rebuild is a success.