I have removed the rear end, spring etc several times for various reasons. The problem that I have had on all of those occasions is getting the rear spring correctly in position in the rear crossmember. The bolt heat on the spring holding it togethere has to go into a hole in the crossmember. With the spring attached to the rear end it is not that easy.
Sooo, the next time I have to remove the rear end I will spread the spring, remove rear backing plates (easy to do), knock out the shackles, remove the speedo setup, radius rods etc. and pull the rear end out. IMO this is easier than dealing with the rear spring. And less dangerous.
Dick