To delete the old authentication method you need access to your WebID-user.
- Go to the WebID-page.
Log in with your e-mail and password.

After log in you will be on a page named "Personal Info". In the menu on the left side you can press "Account Security", and then "Signing in".

At the bottom of this page you will see "Two-factor authentication". You can delete the old method by pressing "Delete".

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If you want to set up a new two-factor authentication, you can press the "Set up Authenticator application" on this page.

You can also follow the instructions on Setting up two-factor authentication for a WebID user.