it took me about 10 min per light. Only worked on the upper half of the headlight though. The lower half facing forward was clean and smooth, so I didn't want to risk scratching it. It is a little bit awkward working around the bulge, but it was easy enough. Just two different sand paper treatments lasting 2-3 min each, and two chemicals. One to clean (1 min), and two coats of the second to seal it up (just allow for 3 min for each coat to dry).