Actually none, axles out, new axles in. Inspect the old axles around the bearing area, normally what happens is the axle is the inner bearing race (like a GM 12 bolt) this surface will wear, it will be apparent in pitting and a worn surface. That will be the key to replacing the axle bearings. You can remove them from the outside of the axle by using an "L: shaped pry bar and a hammer, I'm sure there is some trick tool to do this, but you can crude your way through it with relative impunity and not hurt anything. The new bearings are pounded into the tube along with the new seals, put some aviation permatex around the seal to seal it to the tube. I found a brass drift, or metal tube to "press" the bearing into the tube, just don't beat on the bearing itself, but on the outer race. (recover ALL loose bearings!)
That's really about it, the carrier bearings usually last forever unless the rear has been run dry, you might want to replace the pinion seal, that's about it. No huge deal.