Originally Posted by Simba

1) Reboot the machine and hold down Command (apple key) and S. The system will boot to single user mode (terminal only, no GUI).

2) At the prompt, type "/sbin/fsck -y" (without the quotes) and hit enter.

3) Type "/sbin/mount -wu /" (without quotes) and hit enter.

4) Type "/sbin/SystemStarter" (without quotes) and hit enter.

5) Type "passwd root" (without quotes) and hit enter. You'll be prompted (twice) to specify a new password for root. Once completed, this is your new "admin" password.

6) Type "reboot" and hit enter. Machine will restart normally and you can now use the new root/admin password.