Do you have any image in multiboot before
If not then you first need to format an usb stick with usb format wizard
Mount the formated stick as /media/usb/ in device manager
After that activate Multiboot from greenpanel/pluginpanel
then you get a folder at this location: /media/usb/open-multiboot-upload/
FTP backup image to that location and from plugin OpenMultiboot install image.
After installation in boot menu chose image and it will boot up.
But as mention before if you see logo "Freesat" in minitv display after botscreen you will get no picture
since Tuner is not configured.
You must configure tuner setup to your preferance and satdish, upload your channellists/favorit before any picture