In order to hard reset a LG GW620, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
LG GW620 device will be brought back to the default configuration of a brand new device.
1. Hold down the Power button until the phone turns itself off.
2. Press'n'hold these buttons: Menu + Volume Down + Power button + Camera button.
3. Wait for an LG logo to appear and release held buttons.
4. Your phone will now reset & restart. Well done.