As a last resort, if everything else fails, remove the caliper, and if need be grind away the loops in the pads so that you can get a pipe wrench on the pin and back it out that way. And when you put in your new pins be sure you have anti-seize on there
This is a great idea.
Mike
Yeah, and if you have a small enough pipe wrench--Rigid makes a 6"--you might get away with not grinding the pads off, or just one of them. Or a good bite with the right pair of vise grips might do it, I don't know. Probably need to put the caliper in a bench vise (with protection) or clamp it to the bench. This, in conjunction with an allen (if there's anything left to the hex socket) or with an easyout wedged in there as pictured, and you shall get the victory.