Check that the main cable or the cable to each wheel has not rusted internally and seized up. Happened to another ford I had, had to cut the left read cable and replace the associated parts. Could not loosten the cable like this. I don't know if you have a totally sealed cable, but soak it with some pb blaster for a few hours in combo with this; If the cable seized only at one of the wheels, you might be able to clamp a vise grips onto the cable end somewhere and drive it back with a hammer. Trying to take the rotor off might just not be feasible.
I don't know if these cables are sealed, but this might work anyhow.

 

Well I know the parking brake is burnt up. When I engage it, you need a lot of force just for a tiny bit of stopping power. Kinds pisses me off that this happened. It was only maybe a quarter of the way engaged I guess considering the amount of wear. I have 65k miles, is there any way I can possibly warranty this? My dealer is pretty nice. I hate that this happened and it is the trucks fault for not disengaging properly. And that night it was only 45 degrees.