1.      Copy the ota firmware to the device via USB cable.

2.      Power off the device

3.      Push the “Power” button & “Volume –“ at the same time to enter the recovery mode

4.      Push “Volume-“button to choose “Apply update from SD card” .then push “power”button

5.      Push”Volume-“button to choose upgrade file. Then push”Power”button

6.      Then upgrade is staring

7.      After the upgrade is successful, it will restart.