Under the Reinforced Bumper

How can I get the pieces that hold the reinforced bumper straightened back out without taking it to a mechanic? I'm up for any suggestions.

Assuming you are speaking of the center portion where there is/was a nut and bolt holding the bumper back to the frame.
I would recommend two pair of pliers. I only say this because I am facing the same issue, and from the looks of it, there will be no pretty way around it. The metal must be bent back into it's original shape, then it can be bolted back on.
Chrome

Actually I was talking about the brackets that hold the bumber on. You know where it bolts on either side and is welded to part of the frame, so it can't be taken off and switched with a different piece. The problem I ran into is I can't figure out how to get enough leverage to bend them back down so that they are straight again.