Hey guys, I am about to sell my Dual 1.8Ghz G5 Power Mac. I bought this from somebody used, and it came with Leopard on it. How can I erase everything on it? I am used to a dell where I just pressed two buttons and it just put a clean copy of XP on. Do Macs require discs? I wasn't given a disc when I purchased the Mac, so I sure hope not! Any help would be appreciated. Thanks.