This exactly how I mounted the boxes. IF you look at how it all fits together, you will find that there are two spades that have to attach to the stock connector. Black goes to the side of the connector that has two wires. The biggest problem is the spring clip that holds the light in. I figured out a way to install the new lights without removing the spring clip by fishing the the wires through the clip. The clip unhooks and folds up to remove the light. Make sure you don't touch the new light on the glass area. Make sure the light is oriented right and seated correctly before you close the clip. It is hard to figure this out be looking at it. by doing it will become obvious.