Insert the USB into the TV's USB port while it is powered off.

Up to 3840x2160 UHD, though commonly flashed for 1366x768 or 1920x1080 panels. Hardware: Quad-core GPU, 1GB RAM, and 4GB/8GB eMMC storage.

Power on the TV. The update usually starts automatically, indicated by a blinking standby LED or a progress bar. Do not power off during this process to avoid "bricking" the motherboard.