this is from the instructions that came with my buddy club bumper
"check fit the side skirts. Once fit is confirmed, using a grease pencil, draw a line along the top edge of part to be used as a reference in final installation. Remove part and thoroughly clean the painted surface (using a paper towel and grease remover or lacquer thinner, wipe area on car where the double face tape will come in contact with the painted surface. Do not allow thinner or cloth to remin on the car too long as it can cause damage to the painted surface. Using either of the reccomended adhesion promoters, on a clean lint free cloth, apply a thin uniform coating to the bonding surface, using the minimum amount while fully coating the surface. Allow promoter to dry completly before attempting installation of the part.) Secure the aluminum "L" bracket to the front bottom wheel well using 2 #8 x 3/4 self tapping screws. Repeat other side. Peel approximately 2" of the plastic backing off the tape, making a "tail" from center of the part so that you can position part on car without taking the backing off the tape. Using your grease line as a reference, position side skirts on the car. Once it is in place, pull tail and press firmly to ensure good adhesion. Drill 2 1/8" holes into each wheel well and secure with 2 #8 x 3/4" self tapping screws per side. Also, secure the bottom by drilling 2 1/8" hole through the urethane flange and secure with 2 #8 x 3/4" phillips head screws per side."
wow.. that was alot of typing, i hope this helps, it seems like alot of work, but i'm sure it will be worth it.