I just replaced my rear bumper. The old one was seriously warped after my wife backed into another truck's brush guard, and the newish one that I got looked really good when I picked it up. I put the newish bumper on the truck, though, and it dips down on the outer ends. I understand this is normal for a used bumper, but can it be remedied?

I searched a ton, but didn't find where this had been asked before. If it has, a point in the right direction would be great.

FWIW, I tried to beat my old bumper back into shape, and it didn't work very well, so I definitely want to avoid fubar'ing this newish bumper.