1-turn off your mobile phone or remove the battery if it won’t shutdown.
2-press and hold the following buttons volume up+home button+power button until the phone vibrates release the power button see the photo below:
3-wait for the android logo to appear then release all the buttons.
4-use volume down button to navigate to swipe data/Factory reset , when you reach it press the power button see the photo below :
5-confirm the process , scroll using the volume down button to yes-delete all user data then press the power button .
6-then when finished the reboot system now will be highlighted press the power button to reboot your phone .