Hi Chuck,
These early "straight shaft" PS pump pulleys are always more difficult to deal with than the later "tapered shaft" version. You can use a bearing puller that uses the flat plate clamped behind the pulley. Otherwise use some heat around the center hub of the pulley, screw the nut on flush with the threaded end to protect the threads whey you tap, carefully pry from two sides, and tap with a mallet while prying after heating. You'll need an extra set of hands.