Re: u joint
Here is the procedure from my Clymer manual. Probably a good idea to invest in one. They have a special section just for the L-Drive. Removal starts at the number 13. It doesn't mention it, but I believe there are some snap rings on the inner end of the pivot pins that need to come off. They're to help keep the pins from falling out.
Here is figure 18 that refer to in the instructions above. The center of the pivot pin should be threaded to accept a bolt. Doesn't say what size or thread pitch though. Also the socket of section of pipe has to be larger than the outer diameter of the pivot pin, so when you turn the nut, the pivot pin will pull out.