[NVR-810/1610] How to upgrade the firmware of NVR-810/1610 by USB flash?

Step 1. Download the latest firmware. Change the file name as firmware
(the original one is: firmware.tar.gz). And than put it into USB flash.
Step 2. Shut down the NVR-810. Plug the USB flash on the device and turn
the NVR on.
Step 3. The status LED on the front panel will begin to sparkle in orange. It
means it is upgrade now.
Step 4. When the LED turn green. Means the upgrade is done. Please
remove the USB and reboot your device.