Before you try the factory reset or hard reset on your device, make sure that you have backup your important files. Restoring the default settings or factory reset your device will delete all your existing files and will go back to its initial state.
>>> Switch on your device.
>>> Go to Menu > Settings.
>>> Select Backup & Reset > Factory Data Reset > Reset phone.
>>> Your device will reset to factory settings, and reboots.
>>> Turn off your phone.
>>> Press and hold together Volume Down + Power Button for 15 seconds.
>>> Once Recovery menu appears on the screen, release the buttons.
>>> Select "wipe data/factory reset" by using Volume buttons, and Power button to confirm.
>>> Then choose "Yes -- delete all user data".
>>> Confirm operation "reboot system now".
The instruction provided is the general steps on how to Hard Reset and Factory Reset.If the instruction will not work, please make a comment and we will immediately find the correct procedure. Thanks.