Just order a 03 mach 1 appearance package for the front bumper.. about a 100 bucks for the whole deal last time i checked.. comes with the clips.. easy as pie. Heres how ya do it..
Find the center most hole on the chin spoiler and line it up with this on the bumper to so you can keep it centered,
then use your fingers to get it to your liking on how you want it in relation to the lip of the original bumper.. my upper edge on the chin spoiler is slightly back off the front lip, so it keeps its from protruding to much.
once you got your center hole drilled and the push clip in, go out from there by using your fingers to keep it where you want it and just move out clip by clip.. make sure to put one in every hole to keep it mounted flush.. and WALA! heres the finish product.. took me like 5-10 minutes