I don't mess with kettles, so take this with a grain of salt - just some ideas. First, index the two pieces with a sharpie or a piece of masking tape or whatever to show how they do fit together. Next, trace one piece on a big sheet of paper or something. Trace the other on a translucent sheet of paper. Overlay the two papers. Line them up on the marks where they fit. Rotate the top paper 360 degrees and observe and/or measure what's going on. Plan you work, go slow, and repeat the checking process. The good news is that if the grill bent without cracking the finish, you can probably bend it back. Good luck.