The entire unit should unscrew like a headlight and pull out. You can see the tabs and slots in the picture of the back.
Oh. 🤷♀️ Pics from the back confused me.Jacob, I think he just wants to open the cover, so he can plug in the trailer cord.
Mine hinges on the top, or bottom, don't recall which way
Ok thanks mine does not hinge but it does unscrew I will swap it out for one that does hinge
Here are the photos it was a solid piece.View attachment 174708
It should do this. Curious why yours doesn't. Once you replace it, break it apart and find out. 😁