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If you're talking about the screens that mount around your foglights, black plastic...I just drilled out the ones that came from the factory and saved myself the headache of doing an install (much cheaper too, about 10 minutes of time and no $). Mine's not professional but I have the Z06 screens over them so you can't see much.
There have been posts regarding a pattern for this. Try a search and see what you get.
I just put a set in my car a couple of weeks ago. Total install time was about 2 hours also. No drilling or cutting, but I did get one of my hands stuck in the brake cooling duct opening for a few seconds...
Considering the difference that it has made to my car - the $60 or $70 dollars and the 2 hours of my time were well worth the increase in performance. I found out that without the cold air screens and my hood seal installed (to keep water off of my Blackwing filter) I was pulling most of my instake air from the engine compartment. My IATs were running from 30 to 80 degrees above ambient. With the cold air screens, my IATs are within 10 degrees of ambient.