Then you just unscrew the rear thumb screws. Not only are they use to hold the side panels in place, but they hold the slide out motherboard tray and all the AGP and PCI devices. Our PC20 was loaded with six cooling fans. There are two up front to draw in the cold air. There are two on the side panels, also to bring in cold air.
Exhaust is handled by another fan under the power supply and a chimney fan.
All the fans are 28 CFM Sunon units but AMK will sub in more powerful 50 CFM ADA fans for a few bucks more. The ADA fans are louder however. An optional feature that AMK may offer with the PC20 is a carrying handle. It's in the testing stage however as they're not sure if the aluminum will hold without tearing. We installed it and so far have had no problems.