You shouldnt need to replace a pully,sounds like you are trying to replace the Fanbelt,you have to loosten the alternator bolts move it,then take the old belt off and put on the new one and reset/tighten the alternator,or ask some old git that has a car down the road how to tighten the fan belt and save some grief,pullys rarely need changed,the belt goes first.Good luckx.
Rich, October 2006