To rotate the brake handle on the handlebar, undoing the straddle cable will help to get enough access to the bolt. Once you can pull the brake handle down far enough to see the bolt or screw and if you can get the right tool in there, just loosen the screw a turn or so (not too much), push the handle back to where you want it, then tighten the screw (again, not much if any more than you loosened it). Then re-attach the straddle. Maybe a little tighter, since it did knock loose.

You should be able to release the straddle by removing the wheel and squeezing the brake caliper at the shoes, by hand. That should make the straddle loose enough to unhook an end. You probably will need a helper to hold the bike or the brake, or to bring some more brute strength to the problem.

BTW, it's BRAKE, not BREAK. If you've been having trouble searching Google, that could be why.

I like Anybody's Bike Book.