I've been using Googles Two-Factor-Authentification for for Joomla for quite a while. But after restoring my iPhone i noticed, that the backup didn't include all the configured accounts. I was locked out of my Joomla-accounts without a way to surpass the Google Two-Factor-Authentication.

The following manual describes how to deactivate Two-Factor-Authentication via the database-backend to regain access to the Joomla-backend.