I'd check that the pulleys line up before slotting. You might ruin a perfectly good pulley to try to get it to fit where it won't work right.
Replacing the pump is pretty easy. I think there's about 6 bolts holding it on. Pops right off.
Yeah, if the pump isn't lining up with the bully on the PS pump and alternator (and smog pump and/or AC compressor if you have them, I don't) don't line up the pulleys with the water pump one, it won't matter whether the pump pulley fits or not. The belts will pop off.
