I see your profile shows a 1951 Chev. There is no new production of spindles that I'm aware of but NOS shows up occassionaly on ebay. They do not go cheaply either. You might also search for used ones that aren't worn too flat on the bearing surfaces. As for removing them, search on king pin removal and there should be plenty of tips.

Ed Fallon
In seemlingily endless process of restoring a stock 1953 chev 3100 pickup.