Sometime it can be hard to get out a bushing or race for a ball bearing, press fitted in a blind hole. A well known method is to tap the bushing, place a ball in the bottom and let the tap (or a screw) "press" the bushing out. It is harder if it is a hardened bushing or a ball bearing. In the case with ball bearing race: drill off or destroy the part as keeps the balls. Take away the balls and the inner race. Turn a piece of steel or brass, to lose fit in the outer race. Fill the bearing space with oil. Place the turned piece in the race, like a piston. Hit the "piston" with a hammer and the race will "creep" out. You have maybe to re fill oil for each tap. That hydraulic method is safe and good except for blind holes with a thin or week bottom.