When you remove bearings, do the inside one first then you can push out the outer bearing easily.
If you're breaking knuckles frequently you can stop it by using a rim with less offset. Keep the tires tucked inside the body and they won't catch the side walls.
I needed to do something with my old AM MR01s and added some old MM motor mounts to get the wheelbase for Nascar. One stock body and a custom one I did myself. They now have a new home but, were fun for a while.