Return to Original Firmware

Hi i fucked up und need to get back to Original state. I forgot to set the right wifi to the box. After realisation i resetet the tonie box ans connected it to wifi. It shows up in the web interface but the box says now “Murmeltier” and flashes red. I think i need to start from scratch. So:
How can i return to original FW i have secured everything. Is there a guide?

Thanks =)

Flash back your full flash backup

Thanks i manged that yesterday evening. Just forgot to close the thread =)