Andy, Very carefully break the shine of the area of the bumper inside the letter indentations. Scuff the area good, and yes, it is hard to get to the thin areas, but the main idea is to provide a large area for each letter to grip. You will wash the dust off w/ clear water, dry it, and lastly, the alcohol pads, and allow that to dry. At this point, put the letters exactly where you want them, 'cause brother, they will stick! Don, VIN 6860