I'm not sure if this helps, but I had to remove my bumper last week to install a heavier duty hitch (ones found on the V8). I had to remove my V6 hitch and it required the removal of the bumper. I "think" there were about 5-6 screws I needed to remove on the mud flap and one screw on the bottom of the bumper about midway between the mud flap and the back. There is a plastic fastner you need to remove on each side located just inside the corners of the lift gate when you open it. You will also need to remove at least 2 screws on the bottom on the rear of the bumper and 2 more fastners. Once you have these all off you can pull off the entire bumper pretty easily. Check your clips to see if they need replacing ( you can probably take the clips to the dealer to get replacements ones). You can also see what is causing your mis alignment.
If you have a 10mm socket (all the screws have 10mm heads on them). you can remove all the screws in just a few minutes. A few minutes more for the 6 fasteners.
Oh, one more important note. There is one screw located in a kinda hidden place which may have come loose in your accident which causes your problem. If you remove the screw on the top of the mud flap and peel it down, you'll notice there is one screw in the small opening which secures the bumper to the car. There is a gap about 1" between the bumper and car. I used a 4" extension on a 10mm bolt to reach it. I like 90% sure that this bolt has come loose in your car as it can hold it up perfectly for you.
Sorry I have no pictures, but If you have trouble finding it, let me know and I'll reopen mine up to take some pictures.
