The following steps are intended for the LG Lotus.
Press OK/Menu to display the main menu.
Select Settings, then press OK.
Select More…, then press OK.
Select Security, then press OK.
Enter the Lock Code.
(Note: The lock code by default is the last 4 of the mobile number, unless customized by the user.)
Select Delete/Reset, then press OK.
Select Reset Phone, then press OK.
Once the phone restarts, it will need to be set up for the first time.