As AK_Cowboy states. Grab the corners and pull. It unsnaps. You will then gain access to the wiring.
"Never argue with an idiot; they'll only drag you down to their level, then beat you with experience"
2007 F150 STX Supercab (4.6 2V V8), Edge tuner, factory navigation, H-D headlights, Mark VIII electric fan conversion with flex-o-lite controller.