USB Upgrade
1) Download software to USB disk. Unzip. Copy the image.hex onto a USB stick.
2) Insert the USB stick to the slot of USB Upgrade while HD368Ai is powered off.
3) Keep pressing the OK button and power on HD368Ai. LEDs illuminate and flicker.
4) Release the OK button. LEDs keep flickering. 
Software upgrade is finished when LEDs stop flickering.
5) Power off HD368Ai and then power on again.