I did this on my '87 Carrera today. Replaced the ball/cup and the inner shaft/rod bushing. No need to unbolt the rear coupler at all. I used the 'precision' method that JK911 describes and the shaft rod just slid in nicely. Took about 2 hrs, thanks to the excellent advice here.

Really thankful for this thread. I used all the tips plus 911 manual in addition to specific instructions from J West Engineering that came with the kit and finished the job in much less time than I thought. Made a huge difference in my shifts as the ball cup was completely shot.

One thing that would be helpful was a video which I couldn't find so I filmed my own. Enjoy!

https://youtu.be/YbfhoKd3osE

I want to thank everyone that has helped put this thread together. Special thanks to @jk911 for documenting the steps for getting the shifter back in. I struggled for an hour before finding this thread and once I read the steps I had the shifter in place in 5 minutes!