How to Install MMD by FOOSE Rear Diffuser - Matte Black (15-17 GT Premium, EcoBoost Premium) on your Ford Mustang

Support the rear of the vehicle so you can access the underside of the bumper. Remove (2) fender liner clips to gain access to the (3) 7mm bolt holding the rear bumper trim to the bumper. Remove these on both sides. 

Remove the (2) push clips and (2) 7mm screws securing the factory diffuser to the vehicle.   

Disconnect the reverse light plug.  Gently pull the bottom of the bumper down to access the (4) 7mm screws securing the 3rd brake light to the bumper. Remove the light from the vehicle. Reverse light and hardware will be reused. 

Apply firm pressure to the factory bumper trim to remove it from the bumper. The trim is clipped into the bumper. 

Once the factory trim panel is removed from the bumper, the factory diffuser will need to be cut from the bumper. Do this by cuttng along the dotted lines shown above. 

Install the Foose Diffuser on to the bumper trim. It will clip on the same as factory. Ensure the diffuser is fully clipped into the bumper trim before continuing. 

Reinstall the bumper trim/diffuser to the bumper in reverse order. Reinstall the reverse light using the factory screws. Then reinstall all remaining factory hardware.