Recovery, in Android, refers to the bootable partition, in which the recovery console is installed.
It contains tools to help repair your installations as well as install official OS updates by using a combination of key presses or instructions from a command line sometimes.
Android is open, meaning the recovery source code is available, so that building a customized ROM is relatively easy.
1. To begin please switch off your device by pressing and holding power button.
2. Wait few seconds, and press combination of volume down + home + power buttons at the same time and hold them untill next step.
3. As soon as LG logo will appear on the screen you can let go off the buttons.
4. Now wait patiently untill your phone will load recovery mode menu
5. Congratulations, you are in Recovery Mode screen, to navigate use your volume up and down keys and to confirm use power button.