A few people have been asking me how to do this, so I thought it would be best to post a guide on how to do this.
1. Turn phone off and remove battery, then put it back in after waiting a few seconds.
2. Press and hold the down volume and the power/lock key. The LG logo will appear. Release the power/lock key, then immediately press and hold the power/lock key again.
This will take a few tries to get it right.3. Release all the keys once you see the factory reset screen come up.
4. Use the down volume button to select “YES”. Press the power/lock key to confirm.
5. Wait a few moments until the phone boots into recovery or resets itself if no recovery is installed.
I have used this method multiple times, and it's never failed. Don't worry if you don't get into the recovery screen the first time, it took me at least 10 tries to get the timing right the first time I did it. Good luck