if you have the latest vix on the box then you may have to flash atv 6.4 via usb first as there have been changes to vix that crash the setup script.
During the setup, you will be asked which region you want for freesat, and everything will be setup BUT if you have no sat connection at home you will get an error About the tuner when it boots up after setting up, but once you connect the dish at the van, it should then scan for the channels and you should be ready to go