Take your phone and turn it off – just press power button and select “power offâ€.
Wait while your device is shutting down.
Then, press volume down button and power button together until the LG logo appears on the screen.
When the LG logo is displayed, let go of the power button, keep pressing the volume down key and then press once more the power button.
Once you do that, on your LG G2 the factory reset menu will be displayed.
Press power button in order to agree and wait while the hard reset is being completed.