I have to jump ahead a step here so you understand what you will be doing. You will need a rounded brass punch or in most cases you can use a 11 or 12 mm deep well socket. The rounded edges of the socket will keep from damaging the spacer.
In this picture, you can see what you will be doing when using the punch or socket to drive out the small bearing. This does not require alot of force, merely a few taps with a hammer and the socket will drive out the bearing. A slide hammer can also be employed, but more times then not there is no room to get the jaws inbetween the spacer and bearing.