I forget my password for my MacBook Pro

For Lion/Mountain Lion

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

When the menubar appears select Terminal from the Utilities menu. Enter resetpassword at the prompt and press RETURN. Follow instructions in the dialog window that will appear.

Or see Reset a Mac OS X 10.7 Lion Password and OS X Lion- Apple ID can be used to reset your user account password.

Then try again. If you are asked to enter a password, then do so.

I did the resetpassword on the terminal but when I tried to save it said it wouldnt save the password.