Just did this on my 87 to put a RJC pulley on. Used a special tool that also doubles as an installer as well. Got it on ebay for about $19 or so. Not sure if the 84-5 cars are the same.
The PS pulleys all use the Saginaw type press on shaft so that tool will work on all of the GM's and a lot of Ford and Mopars. That tool will work on both hot air and IC pulleys. I bought the tool at Pep Boys for around $25.