I have an ibook G4 (800 Mhz running OS 10.4) that I got from my son and do not have the install disc. I need to change the password (that I cannot remember). I set it in target disc mode to transfer the files to My MacBook Pro (2.2 GHz, OS 10.5.4). Is there a way to change the password? Can I do it from my MacBook Pro?