1. Connect your UMIDIGI S2 to USB.

2. Start the flashing process with the Download button in the flasher app.

3. Press and keep pressed the power button of your phone until the flashing process starts (red bar appears at the bottom of the app window), then release it. In this process you have to keep the power button pressed for about 10 seconds.

4. Wait until the flashing process finishes.

 

Many thanks to:

Umidigi Official Forum

To the Great Socrate