Flash Image Please

Hi there and special hello and thanks to Nano. I bought the 5800 sx from a chap on flea bay and had to get someone to flash an image that would work on oscam. Is there an easy way to flash these boxes as I have taken a backup image of the Nebula zero image on the box and would like to know how to restore that image should I need to? I am familiar with dm 800 and vu+duo etc and the way you can use the usb port to install the image. Is it possible to flash the backup to this box in a similar way? I had to pay the lad £40 to put on an image and that fancy having to fork out each time the box goes tits up. LOL Any help appreciated.

Hi and thanks. Its an nBox 5800sx running nebulo zero in nand if that is of any help !!!