Recover your Sophos UTM/Astaro Security Gateway w. Screen & Keyboard

Introduction

Played around with your Astaro Security Gateway or Sophos UTM and unable to get to WebAdmin anymore? No worries, if you let the UTM create auto-backups regularily.
Just restore to the last backup from the UTM directly without SSH, just with a screen and keyboard on your UTM!

How do i do that?

Login as root first (a good admin has set a password for that at first setup), then check your last backups with

backup.plx -l

The latest backup should be right at the bottom and starts with cfg_xxxx_xxxxxxxx whereas the x are numbers.
Restore the last backup with

backup.plx -i -n cfg_xxxx_xxxxxxxx

It should say Backup restored. afterwards, so you're done. To be clear, you may want to restart the UTM, but its not necessary!