I've done a few once your down to the shell I take the mig and run a few beads down the inside and let it cool. after cooling they will usually just fall out.they will shrink that much. You can also weld pressed in bearing races and they will do the same thing.I have tried the chisel and made more work than it was worth also have used a die grinder with deburring ball to slit and then pull out but the welder is by far the easiest way I have found. a machinest friend showed me how back when I had to turn wrenches for a living. MUCH EASIER. ozz