Help! Cant get cover off of powermac??


Just bought a powermac G5 from Guitar Center and got shafted on the manual. I need to install an airport card and dont want to break anything trying to get the cover off!
There's a lever on the upper left hand side of the rear of the machine. It has a little picture of a padlock on it. Lift this lever all the way and remove the (looking from the front) right side panel.


P.S. Only do this when the machine is off, yeah?