I cut the tail end off of the old housing and placed a self-tapping screw through the new bulb assembly into the old housing, put the rubber boots on and connected the wires running from the original switch. The lights that I used can be purchased at any auto parts store, no more hunting or shipping & handling charges. I use my tractor pretty early or in the evenings so the headlights are very important. I think I will be replacing the switches soon to rocker or lighted switches.