Well, I finally figured it out on my own. The whole screen thing behind the glass and over the fans is just a single piece held in place by a few magnets. It's like a filter on a cooler except you don't have to open anything. There's an opening on the top behind that front glass panel. Turn the computer off, and just reach down there with your finger, catch the little notch that sticks out in the center, pull it back toward the glass, and the whole screen comes right off. Then you slide it out the top, vacuum it, and put it back.
DO NOT PUT YOUR FINGER OR ANYTHING ELSE DOWN THERE WHILE THE COMPUTER IS ON!
IF THE SCREEN IS NOT IN PLACE, THE FAN BLADES ARE EXPOSED.
IF YOU DECIDE TO WASH THE SCREEN FOR SOME REASON, LET IT DRY COMPLETELY BEFORE YOU PUT IT BACK.