You can reset your password using Recovery Drive, or you can start over in a new Keychain. It will also need a password.
Restart and hold down the Command and R keys during start-up to boot into the Recovery Disk Assistant
On top, in the Menu Bar click the Utilities item then select Terminal.
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In the Terminal window, type resetpassword and hit Return.
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Select your User and type in your new password.
Restart.
Create New Keychain If you do not know the original user password, you should select this option. This will create a new login keychain with the same password as the user account.
Open Keychain Access in Applications/Utilities
Open Preferences under Keychain Access in the Menu bar.
Select General tab.
Click on Reset My Default Keychain
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