If MFA has already been registered for your account, but you wish to make changes to the authentication method.
On a computer, go to https://myaccount.microsoft.com.
Log in using your CampusID credentials (w+ID#@usm.edu) and password.
Select "Security Info" on the left side menu.
From this page, you can add a sign-in method, change a phone number, or delete an existing method.