2 Scoops Hole Drilling

Hey all I've had the twin hood scoops on my car for several years. I recently purchased the 4 1/8" hood scoop seals from Detroit Muscle Technology and I'm ready to make the scoops functional. It looks like I'll need to locate and drill a small pilot hole from the underside of the hood. Once the pilot hole is drilled should I use the 4 1/8" hole saw from the top side or the underside of the hood?