For this article, I was using a Tiger 10.4 version installer disk, because that’s what the client was using. But the procedure should be the same for other versions.

1. Start from System Disk (10.4 installer DVD).
a. If you can’t get to the desktop (Finder) or the keyboard eject key or F12 key won’t eject the drive tray, use other means. One way to eject the drive tray is to hold down the mouse button before the computer starts: keep holding it until the tray comes out.
b. Restart or power up the computer. Hold the “c” key down immediately after hitting the power button or hearing the startup tone. This tells the computer to try and start from the internal optical drive (”c” for CD).

2. Wait for the first install screen to come up. This can take a couple minutes. At the language selection screen, click the arrow in the lower right to go to the next screen. Once the main install screen comes up, you will see a “Utilities” menu in the menus at the top of the screen. “Reset Password” is the second item down under “Utilities”. Select it.

3. Select the disk or volume that has the password you’d like to reset from the list at the top. Then select the user from pull-down menu below that. Enter a password, and re-enter it to confirm in the specified boxes.

4. Click “Save”. You’re done: Quit the reset password utility. All you have to do is restart: you can simply choose Quit from the menu, and pick Restart from the window that pops up, then be sure to hold the mouse button down as the machine starts up in order to eject the Installer DVD.