alright what you need to do:
hold up the back pieces to the location you want. You should have a friend to measure it while you hold it there to make sure it's straight etc. Then mark off where you drill the holes. There are two on the inside of the rear wheel well and one sorta on the bottom of the bumper toward the center of the car. Mark off those spots..drill holes.
wipe off the bumper with a good cleaner, and you'll want to use some adhesive promoter around where the double sided tape is. I also added a wider strip of 3M double sided tape on the kit...but didn't use adhesive promoter...i wish i would have because now i have gaps...
but anyway just peel off the ends of the dbl sided tape enough so that it sticks out of the top...screw in the 3 screws on each side...and then you can grab the tab of the tape and pull it off...pushing in on the kit to get good adhesion. You will probably end up having to add more double sided tape in the future...I need to do that now actually...
hope everything goes well...if you have any other questions feel free to ask