Cannot loosen strut nut

I'm trying to install a cambermeister strut bar, but I cannot take the nut off the strut tower. The threaded stud is stuck to the nut and moves with the bolt. Tried liquid wrench, banging on it, etc. Any way to take off the nut without ruining the threads on the stud? I've tried wrapping the stud, but cannot produce enough grip w/o ruining the threads to force the nut loose. need help! Thanks.

I've found that on the top of all mcpherson strutted cars that it is impossible to get the top nut off w/o an impact wrench. but is a breeze w/one. Sears sells an electric impact (110V) I've had mine for about 10 yrs w/ no trouble. (around $100). good luck