2003 GMC 1500 2wd 5.3 L 130k Front Rotor

I have the front caliper mounting bracket off and the caliper is suspended. But I can't get the rotor to come off the hub. Is it pressed on or attached in some other way. Will I need some type of gear puller or will I need to apply heat or something else to get the rotor off. I have taken rotors off past GM vehicles and they were no where as tight as these are. I suspect I will replace the rears are they going to be equaly as challenging?
thanks