Hey hey hey! No calling dibs. I also think it is the brake carrier bolts. And, sadly, Amanda has already provided the answer = breaker bar and patience. I would add to that: get as much leverage as you can. That is the single most frustrating/hard part of the job whenever those are stuck. If you have air tools, then that's the way to go. THere really isn't any secret or trick to it -- you need brute force.
Best of luck.