You can use either machine or hand. The kit staes its better by machine and actually comes with the machine adaptor, but I disagree on this occassion. The contours of the headlights suit doing the job by hand and this just felt better. Took my time with each grade of paper then the polish. Did try the polish with a drill and the adaptor and all this did was made an absolute mess. By hand and take your time. Also you need to leave the UV sealant out of the sunlight for 15 minutes when first applied, then expose it to direct sunlight for 1-2 hours to cure. Without the sunlight it takes ages to cure so pick a good day's weather or get your hands on a nail curing nail lamp.