You can use heat and that will help. I was a technician(cars) for 15 years and I hated running in to that stuff. Used it myself of course, But anyway, take a hammer and punch carefully tap in the center from outside toward inside one or two pretty good taps. A dead blow hammer does best but any hammer will do. I didn't catch if it is threded to drum or if it has nuts on back side. If it has nuts: Take a frisbie this usually fits perfectly over most rotors and keeps the concrete or debris from gouging or scratching it(Good to use when changing tires too.) place the wheel
with the frisbie and rotor down use a socket (an old one) be sure that it too small for nut and big enough so not to touch the stud. Tap using an extension on the nut. If you tap the stud from the nut side it may swell, so I wouldn't suggest that. Work the nut and bolt back and forth with proper wrenches until its free. I typically go back with blue on the rotor bolts. Be sure to clean very good. I use wd40 and brake cleaner. Hope this helps.