If bent bumper up on truck trying to pull up a tree stump, how can tell how serious a repair it will be?

I didn't pull that hard , and I just barely was budging forward in 4 x4 drive...but maybe the reason it caused it to turn the rear bumper up is due to there being a dirt mound that the chain was going over in between the stump and my truck bumper? ( I was thinking this would give it more upward leverage, but I think this made it turn my bumper up instead), so if I try to pull it this time straight instead of trying to use the dirt mound as leverage, will it pull my bumper back out straight maybe? OR WHAT WILL I HAVE TO DO? just loosen the brackets and push the bumper back down? the bumper is fine, and the brackets don't look bent, so maybe just loosen the bumper bracket nuts and push it back down?