Do turn off the power until the process is complete and the TV restarts automatically.
Download the correct firmware file and extract it if it is compressed (.zip or .rar).
: Plug a standard USB computer mouse into the TV to navigate the Android settings. If you cannot change the IR mapping inside the system settings, you will need to source a cheap multi-brand universal TV remote control and program it to standard Chinese smart TV codes. Conclusion
Insert the USB into the TV's USB port while the power is off.