Keep it lubed .... keep it straight .... and keep it slow. It will come out.
Seventy I'm with Badstang (usernames utlized Justin-case of confusion ) That's CT material my friend.
Other possibilities that might (or might not ) work are: to do as everyone said and go down the side of the Sleazy-Out with a carbide bit. This will sometimes allow the EZ out to slacken up enough (it's loaded into the dog crap metal surrounding it) to be removed with friction-twisting or any slotting you put into the exposed metal (once the tension is off the Ez-out, it wants to come out um, ahhh, easier).
Old school from Grady and my day: Hitting the area carefully with a torch while melting wax around the edges of the EZ out. The wax slides down the thread interface and can act kinda like thread lube.
I've never done it but some will tig a fastener to the broken piece.
Good luck bud.