1.Back up all necessary data. See: Preparing for a master reset on Android.
2.Turn off the phone.
3.Press and hold the Volume Down and Power keys.
4.Wait 3 seconds and press the Back and Menu keys.
5.Note: If you see the LG logo before pressing the Back and Menu keys,
the reset hasnt been completed and you will need to restart.
6.Release the Power/Lock key after you see the LG logo.
7.Release the remaining keys after the LG logo flashes (blinks once).
8.The Android Unpacking screen appears.
9.The phone will restart and complete the factory reset.
Note: If you unintentionally press the Volume Down, Volume Up and Power keys simultaneously,
the phone will display a circle icon with two arrows and ‘S/W Upgrade, Please wait while upgrading…’ message.
You will need to pull the battery and restart.