One thing worth mentioning, it caught me out a while ago..... the grub screw, make sure theres not two in there.
I removed one from a similar setup, it wouldn't budge..... eventually worked out there was two. Although it doesnt look like theres room in this case.
A few taps with a mallet whilst applying a little even pressure often works wonders...
Or, theres threaded holes in the pulley, cant you screw a stud or bolt into them to push it away?