I was able to update the firmware using the 64-bit manager, by performing the following:

1. Factory reset the device - see user's manual
2. Have the USB cable plugged in while it's connected to your helmet
3. Turn on device
4. Turn on camera - one press
5. Press and hold camera button for 5 seconds - at this point, the drive should show up on your computer
6. Power off device
7. Press and hold the phone button for 5 seconds