in installing those arches, you will need to cut the slits on your existing arch - i don't remember if the instructions were included or not... probably not, as they are sold mostly as replacements, and not as retrofits... however, an actual retrofit instruction is floating somewhere for the same lemans flares... i am too lazy - you do the search... lol... make sure you also get the top portion that actually goes onto the metal part of the rear quarter...
good luck...
