Originally Posted by
coolkat
Just use a bench vise. It's easiest if the bike is stripped down, but it can be done with just the wheels off. Put a socket over the end of the cotter, and start cranking down on the threaded part. Cotter should pop out, and be in good enough condition to reuse. I've had success with this method on 4 different cranksets.
I expect a large C-clamp using a socket on the "anvil" end of the clamp and using the screw press on the threaded end of the cotter (with the nut still there to protect the threads) to press out the pin would also work as well.