Thought maybe re-wording a previous post would get better results: On a 2008 Expedition, the rear rotors are frozen to the axle. Beating on them with rubber mallet was no help. How does one remove the rotors without damaging them when rusted solid in place?
Heat the rotor around the hub and hit the back side of the rotor with a 2lb hammer. I've done it a hundred times and it works every time. Then when you reinstall use a little anti-seize around the hub. Sometimes you have to get the rotor pretty hot but it works every time.
Get a regular 2 lb hammer and VERY CAREFULLY give the rotor some very sharp blows on the areas directly between the studs. Just 2 or 3 very short and controlled blows will do the trick. It will fall off like magic. Trust me....been there, done that. If that makes you nervous about messing up the studs, screw a couple of lug nuts onto the studs which will make you less likely to cause damage. Trust me.....I had a big hammer and a torch in my hand once when my friend said "Give me that damn hammer and step back." He laughed and laughed when the rotor literally fell off onto the garage floor after just one or two hits. I learned a very good lesson that day.