After removing the transmission, I disassembled it, had the case and rear cover vapor blasted, rebuilt the shift cam assembly, input, intermediate and output shafts and reassembled the transmission. You can read about that work here.
So, now I’m ready to install it. I also install the clutch throw-out lever assembly, foot shifter assembly, clutch cable and speedometer cable. Here is a link to the documentation about installing the 1983 R80ST transmission and a YouTube video.
VIDEO: 1983 BMW R80ST Install Transmission
Here are the before and after pictures of the transmission.