I am trying to replace a washer in a leaky faucet and have come across a problem. The nut to remove one of the handles is stipped. I have tried vice grips, WD40, and all sorts of pliers and wrenches. Everything I try just continues to strip the nut even further. I can always buy an entire new piece if I could just remove the stipped piece. Any suggestions on how to remove the stipped nut?