If the head is gone: My success has been good with a centerpunch, a couple of sharp hits and the body of the bolt will blast out of the hole. With the remaining bolt & body, vice grips. (Easy out, I've not had great luck with bike bolts.)

The Pletcher-Edges have a serious problem in the design of the tightening bolt. My, so-called, solution has been to torque them to a reasonable tightness and then use thick zip ties around the bolt and wraped around the downtube-bottom bracket to lock them into position. The zip ties seems to provide enough flex-support while keeping the unit locked into position. Does it look like crap? On a dark colored frame it's not noticeable, especially on a touring bike with lots of junk hanging on it. On a 'go fast' bike, it may look like crap but why would you use a kickstand at all on a sleek bike? Problem solved.