WHAT NOW? How's this come off??

That would be my guess. A couple of good taps and you'll know. If it is the right direction, you'll begin to see the longitudinal grooves I mentioned. If not, it will probably start getting tighter. Look very closely and you might be able to just barely see the grooves from one end.

Of course, that's all "out the window" if someone has already replaced the pin with a different type.

Jerry