A Hard Reset reverts a phone to its original settings and a clean OS (Operating System) removing all data and information added to the cell phone by the mobile phone user.
In essence a Hard Reset erases everything from the phone and puts the phone back to like new condition as though it’s brand new right out of the box.
1. Lets start from making sure that your phone is turned off.
2. Now wait 10 seconds and press and hold the power button + volume down button + home button simultaneously.
3. Wait untill you will see the LG logo and let go of the buttons that you held.
4. After a quick moment your phone will boot into Recovery mode screen.
5. Use your volume keys to navigate down to wipe data/factory reset option and select it with power button.
6. And done! Your phone will restart and it's whole data will be wiped out.