I'm in the process of installing the OEM fog lights in my '06 KC LE and I thought I would post a bit of my experience for future reference (I know I sure have benefited from the posts of others) and to fill some gaps in what others have posted.
I bought the lights, trim, and 4 of the "Nissan hex bolts" from http://www.courtesyparts.com/frontier/D40_body-parts.html
. Everything arrived well packed and timely.
Removing the plastic caps that fill the holes in the bumper was straight-forward. After staring at it a bit, I grabbed the front, nurled, portion twisted a little and it came right out. The lights themselves go in very easily. The lower "extension" (in this image
on the left side is actually the bottom of the light) is inserted into an obvious looking "indentation" and the top clip goes in under a "pad" with the screw hole in it. With the wheels turned towards the side I was working on, there proved to be plenty of space to work in.
According to the courtesyparts.com description of the foglights, no hex bolts were to be included. Fortunately, one of the two lights did come with bolts, very lovely stainless steel. I attached the left side light with the stainless steel bolts then proceeded to the right side. This light did not come with bolts so I started to use the hex bolts (black painted steel) that I bought at courtesyparts.com. Unfortunately, they were too short! The top bolt was just barely long enough, but I could not get the bolt to work on the lower "nut". So, I removed the stainless steel bolt from the upper position on the other light and used that one in the lower hole. It's a curious thing that the boxes for both lamp assemblies had been cut open and re-taped. A cynic could imagine someone removing the original bolts and repackaging the lights before selling them.
That done, I pulled down the harness from where it was taped to the wires leading to the headlight and plugged it in. Then came the tricky bit. The one last step was to put in the trim pieces. They have "clips" on them very much like the plugs that originally filled the holes so I figured that it would be a simple push in and twist sort of operation....didn't work. I spent waaaay to much time trying to get those things in and ultimately had to remove the lights so that I could see what was happening with the clips on the back side. Two of the three clips have fairly obvious places (flat areas on an otherwise curved hole) to match up with. So I got the clips "clipped" for those two spots, then pushed the third clip into place. I'm sure there is some "easy" way to go about it but that sure wasn't it...regardless, it worked. I ended up putting a scratch in one of the pieces of trim...with my finger nail!
The lights are not aligned yet and I haven't done the electrical side of things. I'm hoping to have time for that tomorrow or this weekend.
For reference, here's another thread describing the same process: Thread at NissanForums.com
2006 Frontier LE KC, 4x2 in lovely Storm Gray