Headlight install is straight forward. The back of the headlights has 3 ridges that fit inside the adjuster ring (thin, stamped metal). You need to lengthen the cutouts in the metal ring by a small amount for the ridges to fit. For some reason, the Roxor headlights have smaller ridges.
I used side cutters / wire cutters I had in my toolbox.
There is a YouTube video that shows what to do. I also posted a write up on this forum a couple of years ago when I installed KC Hilites headlights.