Did you remove the snap ring first? I just changed my rear bearings and bent the backing plate to with my press. You have to get as close as possible to the axle to avoid this. I wasn't too concerned with it since I converted to rear disc brakes at the same time. The first ones I did about 8 years ago I just took into a machine shop and paid them to do it. I think it cost me about $80 at the time.
