Do not use an Impact!! Find a snap-On truck and get the Wheel Lock Extractor set. I got mine for about $50. If you have a lock off, take it with you an dmatch it up with th eproper extractor, then buy only that one! They are garenteed too so if you break one they will replace it. Mouse milk will penitrate the rust. http://www.mousemilk.com/
Next time use antiseize compound to prevent this.