I personally want the adhesive to be as invisible as possible and waterproof so on the invisible part, Liquid Nails doesn't cut it. I use a clear silicone based adhesive. I clean the mating surface with a Q tip and rubbing alcohol. If you are in a cold place, it may require being in a garage where you let it set up at least at 60 degrees F. Take off the headlight assembly and bring it into the house if you don't have a garage. I use a soft cloth and car wax, I use a hair dryer to dry all moisture before sealing. On the outside of a foggy lens I use very mild rubbing compound or a product called "Scratch-out" then wax it several times, always using a very soft cotton cloth. IPD sells kits for foggy lenses but I have never purchased one.