Microsoft MFA (How to) Remove an Authentication Method
Log in to Microsoft 365 and click on your Person Icon in the top right corner of your working screen and then choose View account from the drop-down menu.
Click the UPDATE INFO link on the Security info tab.
Click Delete next to the method you would like to remove.
You will be asked if you are sure that you would like to delete this method. Click Ok to confirm.
Your method will now be deleted from your Security info, and you will receive a brief notification in the top right corner of your working screen.
If you are done making changes to your Security info, click on your person icon in the top right corner of your working screen and Sign out.
When asked which account you want to sign out of, select your account.
After you are signed out, close your browser.