A hard reset, also known as a factory reset or master reset, is the restoration of a device to the state it was in when it left the factory.
All settings, applications and data added by the user are removed.
The term is often heard in reference to smartphones and tablets but laptop and desktop computers, as well as most other electronic devices, can usually be restored to factory conditions.
1. First you will have to turn off you phone by holding down power button.
2. Then wait few seconds and press and hold power +home + volume down buttons coombined.
3. When you will see LG logo on the screen you can release the buttons that you held.
4. There should appear recovery mode menu after few seconds that looks like this:
5. Now you will have to navigate with your volume buttons down to wipe data/factory reset option and select it with power button.
6. And this is it! you finished whole Hard Reset process.