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 get to the recovery mode you will have to hold down power button to turn your phone off
2. Now when its OFF press and hold combined buttons toghter: Volume down + Power button.
3. Wait untill you see LG logo on the screen, then you can release the buttons.
4. After a moment phone should go in to recovery mode screen.
5. And that's it! Use your volume keys to move highlighted area and power button to confirm.