If you spray it down with a good amount of PB Blaster the night before, it'll be a lot easier to knock out. Close the vise just so it's a red hair shy of the cap diameter, and have your buddy/spouse hold the shaft, and knock them loose with a big-a$$ drift pin, bolt, 1/2 x 4" extension, ball side of a ball-peen hammer, or anything that you can beat on. (Keep it out of the gutter....) DO NOT knock the top cap (the one you're beating on) all the way through, or you'll have a tough time lining it up to drive it out the other side. It'll be rough as hell if you don't spray it down and let it sit for a while, though.
When putting it back together, just use the vise as a press.