If you can get just a small bite on the bearing through the spacer, after a few taps, the spacer should then become "un-wedged" from between the two bearings. Then you just work your way around the bearing tapping as you go. I also used a couple of pieces of 2x4 under the rim while I was banging said bearings out to keep the rim elevated enough to protect the rotor. I just did it a few months ago. Also, put the new bearings in the freezer the night before you plan on installing them and they slide almost all the way in, only require a few taps to seat them.