The vents just pop out the back of the bumper cover. That's the good news. The bad news is you have to take the bumper cover off first. The good news is, you can use the opportunity to clean the junk out of your radiators while you have the bumper cover off. Further good new is that it comes off very easily in like 10 minutes, and goes right back on the same way. It's not nearly as intimidating as it looks.
I've also seen it done this way, but I wouldn't recommend it...
