Had Apple's industrial engineers been more clever, they would have splined the front edges of the side panels, and molded a mating slot inside the side edges of the front bezels. That way, both bezels could have been slid up from the bottom, with a pair of machine screws retaining the main bezel on the underside. Unfortunately, they went with a snap-catch type of assembly, which works better when the plastics are more flexible, than after they have aged for 10 years. There are directions available online that suggest prying the main bezel off with a screwdriver, but that will gouge the plastics where you insert the tip and pry. My method doesn't require tools for the procedure. To do so, the unit needs to be placed on its back end, so either use a pillow under it or remove the motherboard, so that its plastic pull tabs aren't broken off. Straddle it between your legs, with the bottom edge of the cover (and the two release buttons) in front of you. While pressing in on the buttons with your index fingers, apply downward pressure with both thumbs on the face, on opposite sides of the speaker perforations. The idea is to flex the panel downward, so that the sides splay outward slightly, enabling them to unsnap. While you're pushing in the release buttons and pressing down on the top of the cover, lift the computer off the ground with your index fingers. As you're lifting up, the weight of the case will drop it away from the cover, while you're holding onto it. This method has worked for me many times, with my 6400s and 6500s. Incidentally, check out Tom Koons' web site, "
The 6400 Zone," for a lot of useful info about the 6360, 6400, and 6500 Performa/Power Macs.