Yeah, replace the whole thing it.

I have yet to weld mine up yet, havent had any problems, just some sqeeking noises when I go over bumps every once in a while. Its also held in place by the bumper bolts (not the cover bolts, the actual bumper underneath). It will take some work to get the old off, air chisel/die grinder works the best, but you could do it with a cutting chisel and a big hammer by hand. Be careful not to damge the frame rail. If you dont get it welded right away, make sure you torque those bumper bolts down.