I think I will attempt to rebuild my 915 transmission, I have never built or torn down a transmission so I plan to first learn about the process.

The material I currently have is a 911 haynes, a 911SC Bentley and that is about it.
It sems that, at least the bentley manual goes into it pretty deep but are there other manuals available? Possibly the factory manuals?

Any tips or tools that I definitely need before undertaking this?

Thanks