Remove the pto unit and then remove the above pulley easely, spray some nut buster on the pulley and it will come off

I've yet to remove these in one piece...even when I smeared anti-seize all over it. You can try a 3 jaw puller, but you'll most likely end up just bending the pulley. The pulleys are about 25 dollars locally in my area. Honestly, i just air chisel them off, and buy new every time i change drive belts.