I just wanted to add some more information. I had to think about how I had
done it. What you can do is measure the distance that the pulley is from old pump, then press old pump out of pulley and press pulley on new pump same distance then cut off
shaft flush with front of pulley. I used a 4 inch grinder and cut it off. Mount pulley in
vise. The pulley's mass and vise will dissipates the heat, you can also put a wet rag around pulley also. You could try hacksaw but I think shaft is hardened.
