If you have a HDD attached choose the full backup option and choose the HDD as the location.
Then simply FTP the backup file onto a desktop/laptop and transfer onto a fat32 formatted USB stick and use that to flash.
If you don't have a HDD attached; plug a USB in, restart the box, initialise the USB via settings - Hard Disk setup, then backup with the USB as your destination
Your epg layouts, plugins, settings, line and skins will be retained