Admins can review the MFA status for all users and (if necessary) reset the admin status for their users from the Manage Users page.
The user will also need to remove their MX account from the authentication app they are using, so that they can go through the setup again.
Your users should have recorded backup codes when they first setup MFA, avoiding the need to go through a reset if they do not have access to their authenticator app.
You can view the MFA status in this new column. The information will also appear in the CSV export.
You can reset the status for a single user, or, perform this on a multi-selection.