1- Download LYF F50Y Flash file which consist of File, tool & Driver.
2- Install Driver
3- Connect Phone in ON mode to cross check driver installation. It will make port named "Qualcomm HS-USB Diagnostics 9091"
4- It means driver has been installed successfully.
5- Install Flash Tool named Huiye Download Tool for Reliance (After Sales).
6- Click on Select and assign path of firmware
7- It will show 6 file in it, select Get_backup0 (You can select any of them).
8- it will then display the Flash File folder path
9- Connect phone which will enable Download button.
10- Software Upgrade starts.
11- On its completion, Violet area will turn into green and will display a message "Pass" .