Originally Posted by
Metal Cowgirl
.. I've tried both 14 and 15mm socket tool, and both don't fit. There seems to be not enough room for the 14mm to get in there and the 15mm is too big.
All sockets aren't created equal, you might want to try with a special thin-walled socket. An auto parts store is likely to carry those.
Another option is to (arc)weld a nut on top of the bolt, and then use the nut to undo the bolt.