Troubleshooting - OS X - Reset A Local OS X Password
# Reset Your OSX Password With Your Apple ID (easy)
To reset your OS X user password with your Apple ID
If you incorrectly enter your account password at the login window three times, a message appears stating "If you forgot your password, you can reset it using your Apple ID". Click the arrow-in-a-circle icon to bring up the "Reset Password" dialog. Enter your Apple ID and password, then click "Reset Password" to proceed.
Note: In some cases, you may not be presented with the opportunity to reset the password after three incorrect attempts. If this happens, open Users & Groups preferences, remove the affected Apple ID, and then add the same Apple ID back. This issue could occur after upgrading from Mac OS X v10.6 to OS X Lion.
Note: Changing the user account password will create a new keychain. The previous keychain still exists and can be accessed if you later remember the previous password.
Click "OK" in the dialog that appears to inform you about the new keychain.
Enter a New password, Verify password and Password hint fields, then click "Reset Password" to proceed.
Click "Continue Log In" to finish logging in using the new password you just created.
# Reset Your Password From The Recovery Partition (medium)
* Boot into the Mac OS X Recovery Partition (Command-R)
Restart your Mac and hold down the Command key and the R key (Command-R). Keep holding these keys until the Apple icon appears. This indicates that your Mac is starting up. After the Recovery System is finished starting up, you should see a desktop with an OS X menu bar and a "Mac OS X Utilities" window. Note: If you see a login window or your own desktop and icons, it's possible that you didn't hold Command-R early enough. Please restart and try again.
* Select Use English for the main language
* Go to Menu Bar / Utilities / Terminal
* Type the following command:
* From the Reset Password window, highlight your hard drive.
* Select your user account.
* Enter in your new password, confirm the password, type in an appropriate hint.
* Click Save.
* Under Reset Home Folder Permissions and ACLs, click Reset.
* Quit the Reset Password Utility either by tapping (Command-Q) or going to Menu Bar / Reset Password / Quit Reset Password.
* Quit Terminal either by tapping (Command-Q) or going to Menu Bar / Terminal / Quit Terminal.
* Quit Mac OS X Utilities either by tapping (Command-Q) or going to Menu Bar / OS X Utilities / Quit OS X Utilities.
* When the confirmation window appears, click Restart.
* After the reboot, you should be brought to your normal login window. Log in.
* When prompted by the Keychain Utility, select the option to create a new keychain.
# Reset Your Password From The Command Line (hard)
Reboot and hold down COMMAND-S
/sbin/mount -uw /
passwd [SHORT USERNAME]