Can you see a rust ridge built up stopping the rotors from being removed?
As long as the hold down screws have been removed, you can also try some PB Blast and a BFH (big hammer) to get it loose IF you plan on replacing the rotors.
Silly question, but is the parking brake released? Also, there should be a screw (possibly with a Torx or Allen head) holding the rotor onto the hub. You’ll need an impact driver to remove that if it’s there.
You may find a rubber plug in the front of the rotor that you can remove to gain access to the parking brake adjuster assembly. If you’re replacing the rotors it’s OK to hit them from the rear with a hammer to get them off, I’ve had to do this a time or 2 myself on really rusty ones.
It is possible to gain access to the parking brake adjuster with the rotor still installed. Use a long flat head screw driver thru the lug holes while Using a flash light and rotating the rotor locate the star adjuster and rotate it. This might free up the binding rotor.
This happened to me before. I couldn’t not adjust the parking brakes in further. Actually the parking brake lines had frozen up probably due to road salt and lack of use. I ended up beating the rotors off with a hammer as well knowing I had replacements. When you get them off be sure to take care of any parking brake issues you have before putting the next set on!
Mitchell Is saying to release the automatic parking brake slack adjustment before removing the rear rotors.
This is most likely why you can’t get them off.
Just get some slack in the cable what ever way to can, then you should be able to get your rotors off.