How do I mount the rear clearance/running lights

[Makaio]

So I finally ordered the 5 OEM lights that mount at the bottom of the tailgate on the 350's. I originally had a set of JC Whitney cheap stuff. My truck was not originally equipped so my question is how does it mount? There are two round male connectors on the back of the lens and two holes with brass inserts on the backing plate. I'm guessing the screws will have to be countersunk or have a very low profile head because the lens assembly fits flush against the backing and any protrusion from a screw head will fracture it. Also, is one male connector (+) and one (-)? The set I have now is grounded via the backing plate to the tailgate itself.

 

[tugboatphil]

I would imagine that if you are currently using the tailgate as a ground, you could just clean up around one of the screw holes and do the same with the new ones.



However, with as much trouble as I have with grounds, I might run a common ground off the rear of the frame and bring it in to the new lights.