WHAT NOW? How's this come off??

If this is a solid pin is it a taper pin ? If so make sure your driving it the correct way !Otherwise you'll wedge it in there even more.
I'd soak it well with a good penetrant like kroil or PB blaster.
Have a friend supprt the shaft with maybe a big cresent wrench so the shaft does not flex that way all the force will drive the pin out when you wail on it.
Good luck !