Originally Posted by tacxplosion
Take the ram sleeve out and clamp the cap on a padded vise, seeing as how you'll have to take it out anyway for the complete rebuild.
If you care about the ram cap, this is the best option.
If you don't care, get a pair of vise grips, dig into the ram cap and twist hard. Or put into a machinists vise and twist. It likely helps if you heat it with a hair dryer for 10 minutes before doing any of these. It'll heat up any Loctite or old gooey paint and make it easier to remove.