iBook G4 how to reset administrator password when no install disks available

Restart your computer by holding down keys Command + S and type in the following at the command prompt:

/sbin/fsck -y [Enter]
/sbin/mount -uaw [Enter]
rm /var/db/.applesetupdone [Enter]
reboot [Enter]

Once you’ve done that the computer reboots and reruns the setup process.
It will ask you to register with contact details and enter administrator password.

From there you just change all other account passwords in the account preferences.