I have a 1996 Four Winns 170 Horizon with matching Four Winns trailer. My right tail light on the trailer is out, and I'm trying to replace it. I've gotten as far as getting the red lenses off, but that's where I'm stuck. The bulbs are in a clear plastic housing, and I can't for the life of me figure out how to open it. Any suggestions? Or is this something where I have to replace the whole housing? Any and all help is appreciated!