La parte interessante è questa:
How to change MAC-Address of the Fritzbox 7390:
1) Start up FB-Editer and in "Datei" choose "Konfiguration Einlesen"(Means Read configuration)
2) Scroll down to "ar7cfg" part and look for "enable_mac_override".
3) "enable_mac_override" should be set to "yes" without quatation marks.
4) Below "enable_mac_override" there should be a line called "macdsl_override = 00:00:00:00:00;" change it to the MAC address of the ISP router(Can usually be found on the backside of it or via the router's Web GUI)
5) In the FB editor choose "Datei" -> "Konfugration Zuruckspielen"(Means Put data back)
