Prepare the SD card to spoof your Zumo 550
• Insert the SD in your computer if possible. The process will be much slower if it is inserted into the Zumo 550, but it can be done.
• Use Explorer to create a “\Garmin” subdirectory on the SD card. My SD card was listed as the “E:” drive. It may be different on your computer.
• Connect your Zumo 550 via the USB cable to your computer
• Navigate to the \Garmin directory on the Zumo. Mine was listed as the “F:” drive.
• Copy the “GarminDevice.xml” file from the Zumo 550 to the SD card in the “/Garmin” subdirectory. This allows you to fool the downloader into thinking that the SD drive is your Zumo 550 with lots of available space!
• Eject your Zumo 550 and remove the USB cable.