How to Install GT500/CS Rear Bumper Cover w/ Diffuser - Unpainted on your Mustang

1. With a screwdriver, unscrew the 2 screws from rear corner of bumper. 

Located right behind the rear tire 

Repeat on other side 

2. Pry out the 2 plastic rivets from underneath the bumper that is holding the bumper in place.  

Located near the muffler 

3. Unscrew license plate and light. 

4. Inside the trunk, twist off the plastic hand screws and remove the plastic cover that is attached to the trunk.  

5. Unplug the wiring harness that is going into the bumper.  This is for the license plate light and the quarter marker lights that should still be on the bumper. 

6. With a ratchet and 7/16 deep socket, take off the 4 bolts that are keeping the bumper attached to the bottom of the trunk. 

7. Carefully pop out the bottom corners of the bumper followed by the top corners near the tail lights.  

8. The bumper should now smoothly be able to come off the car. 

9. With a rivet gun, assemble the NEW bumper together with provided 8 rivets and stick on the foam guards on the corners. 

Strongly suggest to use OLD bumper as a reference on how the assembly should look. Or review manual if provided.

10. Remove wiring harness, license plate light, and quarter marker lights from OLD bumper. 

Lights should pop right out. 

11. Now, assemble wiring harness, license plate light, and quarter marker lights on NEW bumper.  

Again, use OLD bumper as reference on how wiring harness should be placed. I reused the plastic brackets from the OLD bumper and some electrical tape.

12. Attach NEW bumper onto car.  

13. Pop in all corners of the bumper and screw on all the screws you took off the old bumper. 

Don't forget to pop in the 3 provided plastic rivet screws that go underneath the bumper. Near the muffler. 

14. Plug wiring harness in, make sure bolts inside trunk are screwed back in holding the bumper to the bottom of the trunk.  

15. Attach plastic trunk cover back inside the trunk, screw on license plate, and enjoy your new bumper!