8 3/4 Rebuild Guide?

Buy an extra rear pinion bearing and hone it for setting up pinion depth. This way you don't have to press/remove the bearing you plan on using to adjust the shim pack.

You can do it with a brake hone or a die grinder and carbide cutter. If you have a friend at a machine shop they can use a connecting rod hone.

A Factory Service Manual has a good step by step in it.