Ford Explorer rear brake discs

Hi, I'm currently changing the brake pads and rotors(discs) on my 2003 Ford Explorer XLT. It's the 4WD and not the Sportrak.
I'm trying to remove the rear discs and, according to the Haynes manual, once the roadwheel and brake caliper have been removed, the disc can then also be removed. The manual days nothing about any additional steps prior to removal but my discs will not budge at all. The new discs do not have any type of flange to indicate being secured by the large nut already present on the wheel hub, so as far as I can see, the old discs shouldn't be secured this way either.
Any clues to assist with removal?
Thanks.

 

Some rotors have set screws, usually 3-4 of them. If there are no screws, it may just take a good mallet to whack them loose.

Having to change the rear pads and rotors on a 2003 model already is odd, usually they will last for many many years before needing replacement.

 

Sometimes you have to hit them squarely with a hammer on the area that fits over the hub to break them loose. If they are loose on the hub and won't come off, it is do to a ridge of rust build up on the rotor behind the parking brake shoes, causing the rotor to hang up on them.

 

Thanks guys - the Big Hammer it is!