I have a 24" white iMac. The model just before the aluminum iMacs. How do you open the case? I've opened the Mac Mini using a pair of putty knives. It's not to hard. Does the iMac open the same way? There must be some good videos of this on the web. Anyone have a pointer to good instructions? My iMac was a 240GB disk inside and I notice the local Frys store has 750 SATA drives for $149 each. Would be a nice upgrade.