Forget that new super secure password you just created?
Breathe easy, there is a simple fix. In OS X versions 10.6 and earlier we would just boot to the installation disk, go to Utilities, and open the Reset Password application. In 10.7 and 10.8 Apple has removed this option from the menu, however there is an alternative way to get to it.
In order to get to the Reset Password application in 10.7 or 10.8 we will need to boot to the recovery partition by holding down the “Option” key at startup.
Next we should see at least 2 drive options. Select your Recovery HD and click on the arrow beneath it.
Once booted to the recovery partition go to “Utilities” in the top menu and select “Terminal”.
There should now be a prompt that says –bash-3.2# or something similar. Type “resetpassword” and hit return on the keyboard. A new window titled “Reset Password” should appear. Go ahead and close the Terminal window – we won’t need that anymore.
In the Reset Password application select the drive and account location that we are resetting. Next, enter the new password in both fields (and a hint if you like) and hit “Save”.
We should get a pop up indicating the keychain may need to be updated. Go ahead and close this dialog and the Reset Password application.
Finally, go to the Apple menu and select Restart. That’s it! You have successfully reset your password.