Alright everyone, I need a little help.
I had one of Brent's knurled chrome pillion seat bolt on my America. http://newspeedmaster.com/html/pillion_seat_bolt.html

I noticed a few days ago that it was missing and wasn't sure if some snotty teenagers had stolen it or if it had vibrated loose, but I got a replacement anyway.

I went to install it today and saw that neither of the above options was true, but that the top had sheared off and left the stem of the bolt thoroughly inserted in my fender with no easy way to get it out. I can feel a tiny bit sticking through, but it's awfully tight under there and I am pretty sure I could not get a set of vise grips in there to turn it.

Any suggestions? I think it would drive all the way through the bottom if I could figure a way to turn it.