I did mine last week (80 300td)and didn't have to touch the sleeve nut. I removed all bolts from my front flex disc and pulled the (well marked)front section of the shaft forward out of the spline and out of the car. I didn't take out the ebrake linkage as I wanted to keep the car from rolling off the ramps and on me. I left the rear flx disc on the diff but removed the three bolts that attached the disc to the shaft. With the two bolts out of the support, the rear shaft easily came out rearwards. The support took a while to pound off the bearing, I used a heavy hammer and a chisel and kept knocking till it slowly came off. The old one made the perfect tool to pound the new one on. Do not mung up the splines. As mentioned be careful, to match them up correctly, mine only wanted to go back the right way, I put fresh grease on the spline. My front disc was shot as was the support but the rear disc was fine. It was helpful to roll the car three feet to rotate the shaft to make the last flx disc bolts accessible.

All that horrible vibration is smooooth.
Good luck.