Make sure your Bad Elf Flex is running firmware version 1.0.19 or newer. If not, update your firmware first.
Download the desired GEOID package(s) to your PC or Mac using the links above.
Copy the file(s) to any FAT-formatted USB drive, and cleanly unmount/eject the USB drive from your computer.
Turn your Bad Elf Flex unit ON by holding the power button for 3-4 seconds, and wait until you see the main LCD screen (~30 seconds).
Plug the USB drive into the supplied USB-OTG adapter cable.
Plug the USB-OTG cable into the Mini-USB port on the back of your Bad Elf Flex.
The left LED should illuminate with a purple status indication, indicating the OTG cable was detected.
The LCD screen will display a message indicating the USB Drive was detected.
Within a few seconds, the Flex will start the update process. You will usually see the all the LEDs turn purple during the update, and the screen will display a "Shutting down..." or "Updating firmware..." message.
The GEOID packages can take 1-3 minutes to install depending on the speed of your USB drive. You may or may not see any progress indication. Be patient!
When finished, you will hear 2 beeps, and the firmware will automatically restart.
You can safely disconnect the USB drive and USB-OTG adapter cable from the back of your Bad Elf Flex.
To configure the Bad Elf Flex to use a GEOID model, pair your Bad Elf Flex with your phone or tablet, and open the Bad Elf Flex app.
Navigate to Flex Settings > Elevation/Orthometric Height to confirm the GEOID package is available and select your desired model.