Ok, get the puller as Duke showed you or put the pump up in the arborpress. I have a little kickpress I use to keep from putting too much pressure on things, blocking it up and putting a 3" long bolt just a touch smaller than the shaft between the ram and the power steering shaft.
Get a couple of short pieces of wood, you'll need them. Go grab that little propane torch you have. And a pr of thick welders gloves.
Light the torch and start about 1" away from the outter edge, start heating this pulley in a circle About the 4th round, start spiraling in with the torch, and when you get in right next to the hub at the shaft go around about 4 or 5 times.
After its thoroughly warm, grab your gloves and go to jacking with either that pulley or the press. Shouldn't take too much, you'll here a 'pop' and get her off there fast.
When you go to get that pulley on your new pump, grab a deadblow hammer or a rawhide hammer, put them up on your worktable. Take your pulley, put it in the oven on a cookie sheet with your wifes permission, heat to 450 degrees for 30 minutes. Go to your work table, put a coating of antiseize on your new pump's shaft. Drink a cold one.
After the pulley is baked for 30 minutes, with your thick welding gloves and a thick rag, take the pulley to your workbench. Grab the new powersteering pump in one hand, hold the pump so the shaft is horizonal, with the other gloved hand, start the pulley onto the shaft. If your lucky it'll slide on. If not, grab that rawhide hammer, give it a good tap, and usually its about in the edge of the pulley is on the edge of the shaft territory. Tap it on the hub, with a piece of wood.
Get it where you want it fast, cause that pulley will grab ahold of that shaft fairly fast. You can press it on, won't take much pressure, usually a hammer you can tap it on.
Hold the pulley where it needs to be for a few moments, then, lay that pump so that the pulley is sticking straight up, with wood under the pump, so the pulley will cool. A small fan blowing in its direction will help things.
Don't go hitting your pulley with a regular hammer, and when you do smack it, use a piece of wood between the pulley hub and the hammer. When its hot, you should be able to just tap it on. If its hot enough, it'll just slide on if your quick enough....