The method I used to replace the Rear pillow balls, was the socket/washer/bolt method. You get 2 sockets different sizes, and use a ratchet to tighten up the bolt going through the pillowball, and eventually, the tightening of the ratchet forces the small socket to press the pillow ball out into the larger socket. The same method is used to reinstall.
Here is a link that will better explain what i'm talking about.
http://www.maxcooper.com/rx7/how-to/...lls/index.html