Reset MFA

It also possible to change a user's Authentication methods by following the steps mentioned below:

1. Please login to Azure Active Directory by logging in to https://aad.portal.azure.com/
2. Click on users and select the user in question
3. Click on authentication methods
4. You can update Phone, Alternate phone, Email and Alternate email from this screen
5. (Optional) You can click on "Require Re-Register MFA" to reset MFA settings

We attached an image as a reference.

To just reset MFA, please follow the instructions mentioned below:

1. Please log in as a global admin to MFA settings by going to https://account.activedirectory.windowsazure.com/UserManagement/MultifactorVerification.aspx
2. Select the user in question
3. Click on "Manage user settings"
4. Please check "Require selected users to provide contact methods again" and click save