its easy, I had to take a non fog headlamp and convert it for my car, you just need the projector assy itself, the wires to plug it in are most likely still in the light
theres the "dummy" piece thats in the headlight. Theres 1 or 2 small phillips head screws holding it in place, you take that out and bolt the fog assy in.. unfortunately I didnt take any pics when I painted my bezels and installed my HID