Good thing is that you aren't seized with corrosion...that's where my problem was for the drill out. I would turn the bolt back in and cut it off with a very thin kerf hacksaw/sawzall/dremel blade at the split. Remove the nut side which should come out easily...most likely bent right at the pinch point, so if you cut it there, a little help with a punch while turning the bolt head and it should come out. Again, don't be tempted to drive a wedge into that upright split, you will crack an ear and then be in for a full upright replacement.

Good luck with this!