UZ214

I got into a fender bender couple of weeks ago; a lady bumped into the car on a red light ..I had the bumper fixed and everything from a body shop. The tab that holds the top left bumper/ under trunk is broken from the impact, besides that its fixed and you cant tell if was ever repainted...but there is a slight gap in the bumper/body that is driving me nuts on both sides. I am going to order a new bumper and install it myself but I cant find any DIY instructions. i can take it back to the shop but they are not going to do a better job than I am. I am getting a new bumper painted and shipped to me.

Any help is appreciated!
thanks