I take it you're working with a Chevy? On the C clip style rear ends, the easy way to do it is instead of messing with a slide hammer, get a length of 1/2 ID EMT. About 6' will do. With the axles out, simply slide the EMT in from the opposite side of the bearing you want to remove, place the end against the bearing (you my need add a slight bend in the EMT to get it to line up right), the give the other end a few good smacks with a hammer. essentially, you use the EMT as a large drift punch. I won't say it will not damage the bearing, usually if I'm taking bearings out the housing, it is to replace them, so I'm not really concerned about damaging them.
