Vice grips work. Just took apart some new kegs. Not sure the fuss or maybe if I got lucky, but even one of the ultra stubborn ones came off without much work. Could by my incredible skill, or amazing manly power. YMMV.
Vice grips worked of a few that I couldn't remove with the pin
lock socket. the special pin lock socket started bending the pins the posts were so stuck. The vice grips abd a hammer loosened them up. You can clamp the vice grips all the way at the bottom of the post, below the pins.