Topic: Restore TL-MR3020 to Original

Helly everybody,
could someone please tell me how i could restore my TL-MR3020 where now OpenWRT is running. I Also opened the box of my TL-MR3020 and i can connected over Serial to an PC (that also works ).
Before I loaded the OpenWRT Image (*.bin File) over the Webpage of my TL-MR3020, I made an backup. Now I want to load this Backup on my TL-MR3020 !