To reset the administrator password using the Mac OS X disc:
If you don’t remember your administrator password, you can reset the administrator password using the Mac OS X Install disc. Follow this instructions.......
*Insert the Mac OS X Install disc and restart the computer.
*When you hear the startup tone, press and hold down the C key until you see the spinning gear.
*When the Language Chooser appears, select your language and click Continue.
*Choose Utilities > Reset Password.
*Follow the onscreen instructions to change the password.
*Quit the Installer and restart your computer while holding down the mouse button to eject the disc.
*You can change your login keychain password in Keychain Access to match your new account password to unlock your keychain when you log in.
Important: Any user with the Mac OS X Install disc can gain unrestricted access to your computer, you should keep the disc in a safe place.