In order to hard reset a LG GD310 , you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
LG GD310 device will be brought back to the default configuration of a brand new device.
1. Turn on the phone by holding down the Power button.
2. Press the Call button in order to open the dialer.
3. Enter one of these codes into the phone - 2945#*101# or 1809#*101#
4. Press the Call button once more to complete the hard reset process. Yaay, done.