Reset password

The following guide explain how to reset a user's password in the last couple of Mac OS X versions. This is meant only for local accounts.

Reset 10.4 Tiger password

1. Power on or restart your Mac.
2. At the chime (or grey screen if your chime is turned off), hold down Command+S on your keyboard to enter single-user mode.
3. Type sh /etc/rc and press Enter/Return.
4. Type passwd username and replace “username” with the short name of the user account for which you’d like to reset the password.
5. Type your desired password and press Enter. It won’t show itself on the screen, so be careful what you type. You will most likely have to enter it again to confirm.
6. Type reboot and press Enter.

Reset 10.5 Leopard & 10.6 Snow Leopard password

1. Power on or restart your Mac.
2. At the chime (or grey screen if your chime is turned off), hold down Command+S on your keyboard to enter single-user mode.
3. Type mount -uw / and press Enter.
4. Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist and press Enter.
5. Type ls /Users and press Enter. This lists all of the usernames on the computer – helpful if you don’t know or remember what these are.
6. Type dscl . -passwd /Users/username password and replace “username” with one of the users displayed in the previous step. Replace “password” with a new password of your choice. Press Enter.
7. Type reboot and press Enter.

Reset 10.7 Lion & 10.8 Mountain Lion password

1. Shut down your Mac and turn it back on while holding down the Command and R keys at the same time until you see the Lion Recovery screen.
2. From the menu bar at the top, select Utilities > Terminal.
3. In the Terminal window type resetpassword and press Enter.
4. Use the Reset Password utility to select your hard drive, choose your user account, and enter a new password.

Alternative for all OS X versions 10.2 - 10.8

This method will trick your computer into thinking it is starting up for the first time. It will take you through the registraiton process where you will get a chance to create a new admin account. After that you can reset the password for any previous users under System Preferences -> Users.

1. Power on or restart your Mac (should work for any Mac OS X system).
2. At the chime (or grey screen if your chime is turned off), hold down Command+S on your keyboard to enter single-user mode.
3. Type mount -uw / and press Enter.
4. Type rm /var/db/.AppleSetupDone and press Enter.
5. Type shutdown -h now and press Enter.

References

1. http://www.macyourself.com/2009/08/03/how-to-reset-your-mac-os-x-password-without-an-installer-disc/
2. http://www.macyourself.com/2011/08/20/how-to-reset-password-for-mac-os-x-10-7-lion/