Here is the instruction for how to flash the stock firmware on M8 Amlogic S802 tv box:
Because there is no OTG port on M8, so you can’t connect your M8 with PC and use usb burning tools to flash. You have to use SD Card to flash the stock firmware.
Here is the step by step instruction:
1 Download the firmware from our blog, usually you will get the following files:
2 Prepare a SD card, and format the card, copy the three – Make sure your device is powered off and power cable removed.
3 Insert SD card with extracted files in root directory.
4 Insert a match or a toothpick to reset button – you will feel a click. (the reset button is in the AV hole in the back)
5 Power on the M8 tv box by inserting power cable, while holding the match in the reset hole.
6 It will boot to recovery and start installing ROM. Good. It will restart when finished (you can connect with HDMI cable, so you can see the update process in your tv or monitor)download file to this sd card.
I am still working on how to flash the M8 box via PC, when i get answer, i will update the post here.
Enjoy, any questions, feel free to contact me.