I own a 97 F150 4x. When I tried to remove my front rotors last year they were rusted on so bad that a sledge and torch would break them loose. I used a Saws All with metal cutting blade and had them off in less than 5 minutes each. The down side is it ruins the existing rotors but mine had to be replaced anyway. Just cut down through the rotor preferably through one of the hollow cavities in the rotor to the hub. Take a large screwdriver and drive it into the cut you just made. The screw driver expands the rotor and it pops right off. Worked like a charm.

 

Just anti-sieze the hub after cleaning the existing rust to prevent this again.

 

I took a fireman's sledge to mine and they broke in pieces on my 97.