Check out www.carcareonline for all you would ever want to know about chip repair. Basically, since the nick is probably down to the metal, you will want to buy some grey primer paint at an auto parts store. Then, clean the chip area with some isopropyl alcohol. Using the tip of a round wooden toothpick, apply a thin coat of primer to the area. Let dry. Then use same technique to apply a thin coat of touchup paint. Thin is the key. Let dry. Repeat this several times until the chip is filled in, then another coat so that chip area is just slightly higher than surrounding area. When dry, I use detailing clay (sold in automotive paint supply stores or online) to rub the chip paint even with the surrounding area. I did not have much luck with the sanding technique recommended at carcareonline. Hope this helps.