How to change your user account's password on your Mac if you wish to have a stronger password or if it's been compromised.
2. Change User Password
It's important to change your login password from time to time to protect your privacy.
Click the Apple menu (1), then click System Preferences (2).
Click Users & Groups.
Click Change Password.
Enter your current password into the Old Password field when asked.
Enter your New Password (1), then type it again to Verify (2). You may also enter a Password Hint (3) to help you remember what your new password is. Click Change Password (4) to complete the process.
For help choosing a secure password, click the Key button next to the New Password field.