" Is it difficult to install the Headlight, Fog ligt, Signal light kit? "
Do it on a warm day. That's talking from expeience. A hairdryer really doesn't cut it.
Also, I had to trim a little excess shield from the headlights. Remember sticking a 2 dimensional sheet around something thats 3 dimensional is a bit tricky.
I wouldn't do the fogs or drls again, because of moisture, dirt and grit getting around the periminter of the lenses. I know the average joe couldn't see them, but I sure could.