STEP 1: Download and Install USB Drivers on your computer. In case you have already installed them, you can skip this step.
STEP 2: Switch Off your android device .
STEP 3: After downloading Stock Firmware , extract the zip file on your system.
STEP 5: Form the files listed run the Flash_tool.exe file.
STEP 6: Once the SP Flash tool is started, click on the Scatter-Loading button located in the right side.
STEP 7: Now locate the scatter file in your stock ROM. It is generally located in the bin/ directory.
STEP 8: Now click the Download button to start the downloading process.
STEP 9: After completed all the above steps, connect your Android Device to your system using the USB cable and , press any button other than power button so that your system will detect your Android Device. You can use volume buttons.
Step 10: Once the flashing process is completed, a green ring will appear on your system. Now disconnect your Android Device and switch it ON.