so you want to remove your overlays for good? Are they just a standard laminx type film that you applied? I'm guessing it is - you'd probably need to get a heat gun, or hair dryer on that film to heat it up - and try to get the adhesive to soften up. It's going to be a matter of heating it up, and getting and edge loose with a razor blade, or something thin.
If you want easier access to mess with stuff, you could always take the fog lights out all together, but you'll need to remove the front bumper.
this shows how the front bumper comes off. (you obviously won't be removing the headlights). When you get to the bumper removal, there will be two plugs that are wired into the foglights. You have to pull those out of the back of the foglights to get the bumper loose/off the car. The video below has no fogs (so that won't be in this vid)
then, it's a matter of a few screws and you could mess with the fogs out of the bumper itself.