I’m going to have the swing arm powder coated. So I remove the drive shaft to avoid any possibility of damage to it and the swing arm bearings. I will replace the swing arm bearings as they are likely 40 years old and there is rust in many places on the bike so it’s possible the swing arm bearings have not been cared for.
I use a tool from Cycle Works to pull the bell housing off the end of the drive shaft that fits into the rear drive unit. Then the shaft slides out of the swing arm housing toward the transmission end of the swing arm. The tool made it very easy to remove the bell housing. The housing is secured by a nut that is torqued quite high and by a taper in the housing and the end of the drive shaft, so it can take a lot of leverage to break the bell housing loose from the drive shaft. Mine came off quite easily.
You can read about how I do this work here:
Here are a couple pictures from the write-up.