Rear Shaft Bearings
When I replaced mine, I also replaced the shafts...but with everything I read up to that point, getting the old bearings and retaining ring off the old shaft can be a bit of a challenge. Heat should work well, but most folks state they snap the olds parts in two with a hammer and chisel. This is a bit risky if you miss and hit the shaft. suggest trying the heat method first.
When I pulled my old axle out, the inner race stayed in the housing. With a slide hammer, it didn't take much to really pull it out of the axle tube. The new bearing was still in one piece. This is normal and correct. Once the rollers wear into the out race over time, it too will split into two pieces.
I used a 12ton press to get everything onto the axle, but is a tight fit and will require perfection for being pressed straight. Pre-grease the seal and slide it on. Then press the bearing on till it stops at the shoulder on the shaft. Then Press the retaining ring on. Make sure the retaining ring starts straight and presses straight or you probably will not get it on. I have also heard folks with large presses, and not pressing straight, causing the new ring to split...and not showing up until later on the road. Once on, if you made a mistake, you will probably have to order all new parts again and start over. Pay close to the orientation of how things came off and ensure the new stuff goes on in the same order and orientation. Just for my own piece of mind, I took measurements of everything, and compared to the new to ensure I ended up exactly the same.
I am not saying my way is the best, just saying this is what I did on mine and it worked well. I do have a bit of experience with high speed manufacturing equipment, but had never seen bearings being held onto shafts in this manner. Although I don't like it necessarily, I can't complain about what seems to be working well.