hello, as a hobby i fix macs. I do things like adding ram swapping Hdds. but am not really god at the software part. I got a costumer with a lock macpro that does not has the password. I know it sounds suspicious but hey he is just another costumer. Would you guys help me? I am getting the machine tomorrow so i need TO KNOW IF is possible to just put a Leopard disk and restore it? or will i have to do thing further like Formating the HDD or swapping and put another clean one to install OS X on it?