seriously......looks like the angle/clearance would make it tough to get a drill in there to drill for an easy out on the broken bolt .
Unless the axle turns enough ...then just drill it and use an easy-out.
Worst case, drill it out and re-tap next thread size up
otherwise, looks like there "might" be enough bolt showing to get a VisGrip on it.
if you haven't already used penetrating oil (PB Blaster is one of the best..WD40 is only "OK") ..and if you didn't spray penetrating oil on it first...shame on you..get a can of PB Blaster
worth a try letting PB soak awhile then putting the VisGrips to it...if it mangles beyond VisGrip bite in the attempts..then it's the grinder
(if you can get a drill and easyout to it)
..L.T.A.