Using this rear fog light overlay sticker is easy. First, make sure your hands and the area where you'll install the sticker are clean. If you find the alignment isn't right when you start putting it on, use soapy water with just a little soap in it. You can put this water on the lens and the back of the sticker. It'll help you slide the sticker into the perfect position. Once it's in place, use your fingers to push out all the water and air bubbles. To speed up the drying process, you can use a hair dryer or a heat gun, but be careful. If the heat is too hot for your hand, it's too hot for the sticker. As for maintenance, just clean it gently with a soft cloth and mild soap from time to time. This will keep your fog light overlay looking great and ensure it continues to work well.