How to change language of Fritz!Box from German to International

Solution 1:

ruKernelTool

You'll need a Windows image for the process, but ruKernelTool allows you to do what you want. The tool and website is in german, but the process is pretty straightforward:

1. Start the tool and agree to everything.
2. Click the download tab and allow it to update its links to the AVM servers
3. Select the firmware you want, in this case 7390 International 84.06.20. Click Download.
4. Switch to the Network-tab (Netzwerk) and click the Media-Sense item to turn it off. Windows will reboot.
5. Go back to the Downloads-tab and select you downloaded firmware and click the kernel source button. (als Kernel-Quelle verwenden)
6. You should switch to the Upload-parameter-tab and enter your WLAN key from the bottom label on the box.
7. On Upload-tab click the Validate button and it will list out if your choices check out. It will provide warnings in German so you might want translate.google.com handy. (Uberprufen)
8. Finally start the upload to the device. (Upload starten)

If all goes well your router should reboot, Windows will reactivate Media-Sense and reboot, and your router should have a language selection option. Your router should be accessible via http://fritz.box