I'm guessing you got all the lug nuts off right?
Sounds like its just stuck on...so here's what I do if I cannot get it off with the Persuader (The Persuader is a really effing big mallet, really big, or a pry bar).
BE CAREFUL DOING THIS...I loosen all the lug nuts up, just a little, maybe three or four turns from tight, and drive the vehicle just a little, turn if you need to, or just dropping it off the jack might do.
Then lift it back up and it should have come off. Once loose I will typically apply grease or anti-seize to the rotor's hat and back-side of a wheel to assist in future wheel removals. Yes, they will corrode on if infrequently removed.
And no there is no trick to removal...