To change your workstation user account password on your Mac once logged in:

1. Navigate to the Apple icon in the upper left-hand corner of your screen and select "System Preferences":

You can also open "System Preferences" by clicking on the "System Preferences" icon in your Dock:

2. Once the "System Preferences" window loads, click on the "Accounts" icon located in the "System" row:

*Note: Newer versions of OS X have changed "Accounts" to "Users & Groups".

3. Once the "Accounts" window had loaded, verify that you are able to make the changes to reset your password by observing the state of the "Lock" icon in the bottom left hand corner of the window.

If the icon is in the "Unlocked" state, proceed to Step 4.  If the icon is in the "Locked" state, click on the icon and enter your current workstation user account username and password, then click "Unlock".

If you entered your username and password correctly, you will be directed back to the "Accounts" window and you will observe that state of the lock is now "Unlocked":

4. Once you have unlocked the "Accounts" preferences, click your username under the "Current User" section, and then click "Change Password...":

5. Proceed by entering your "Old password", followed by your "New password".  Enter your new password once more in the "Verify" field:

6. Once you have filled out the password reset form, click "Change Password" below the "Password hint" field to submit your changes:

7. Provided you have entered your "Old password" correctly, followed by matching your "New password" with "Verify" - you will be directed back to the "Accounts" preferences window:

*Note: For security purposes, be sure to click the "Unlocked" icon before closing the "Accounts" window in order to prevent any further changes: