What is the best way to format my harddrive on my imac g5? I am selling it tomorrow and I don't want the new guy to be able to restore anything. Would just using the OSX install disk work fine or is there a better way. I have already backed up my iTunes onto dvds and im doing iPhoto next. I dont have an external HD so i am using my 80 gig ipod for the rest of my files and aps.