If you forget your lock sequence and backup PIN, you will have to perform a hard reset to gain access to your phone.
Performing a hard reset deletes all of your user data, which includes pictures, videos, and music saved to your internal memory. Please make sure to back up your information prior to performing a hard reset.
Turn the phone off.
Press and hold the following keys at the same time: Volume Down Key + Power/Lock Key on the back of the phone.
Release the Power/Lock Key only when the LG logo is displayed, then immediately press and hold the Power/Lock Key again.
Release all keys when the Factory hard reset screen is displayed.
Press the Power/Lock Key to continue or either of the Volume Keys to cancel.
Press the Power/Lock Key once more to confirm or either of the Volume Keys to cancel.