Here are the step to change your main account’s username’s password.

1. Log into the Customer Control Panel with your main account’s username and password.
2. Click on the “Account” tab.
3. Click on the “Admins” link.
4. You’ll see your username, to the right of it you’ll see the “Change Password” link, click it.
5. Type in your current password.
6. Type in your new password, then retype in your new password again
7. Click Finish.

You’ve completed updating your main account’s username’s password.