1) Apply a good penetrant like Aero Kroil and let it sit at least an hour.

2) If you have access to a welder, weld on a bolt and remove.

2) If you don't, try and get some heat on it to "melt" the "blue" Locktite, and then try the TORX method Strife stated;

IMHO, I would rather try and DRILL out the bolt with a LEFT-hand cobalt-bit, rather than try and use an EZ-OUT or similar instrument, because if those shear-off, (and they do!) you are SOL.

Good luck,
:-) neil