Thanks for that link. It was exactly what I needed. It was easy to peel back the inner fender. Once you get in there with the help of one of the photos in that thread it is pretty easy to figure out where the spring clip, U-nut and bolt go. Everything looks and works as it should. I see there is an adjustment for the light. I checked to see if they both were shining at the same height. I am assuming that they are correctly adjusted from the factory since they know exactly what vehicles they are going on or should one check that before buttoning up the fender liners? Thanks.
I wouldn't assume they are set correctly for the factory, because there's too many different Frontier models these go on, not just one - 4x2, 4x4, base S, Pro-4X, Crew Cab, King Cab, SL, SV, etc. and I would bet that none of these are identical in terms of ride height, body angle, and so forth. Just leave the lowest 3 screws (2 underneath, 1 at the forward wheel well area) out, wait until it's dark out and find a flat wall you can park 25 feet away from (I usually use an underground parking structure, they always have flat walls with enough space and it's always dark enough) and check the angle there. Adjust if needed.