There are 2 "dowel" locating pins joining each rotor and hub. The screw came off no problem. I sprayed the rotors with PB Blaster and tried using a crowbar and also tapped round the edge lightly with a hammer on a cloth, that didn't work. If I was back in Georgia on my own property I would whack them with a big hammer. Trouble is I'm in an apartment complex in Houston at the moment with a strict no car repair policy! I had to sneak out this morning to a quiet corner to work on it. I've done a bunch of rotors in the past and never had a problem, they usually fall off.
Colin