Extract/Unzip the LG Flash Tool 2014 .zip file that you downloaded above on your PC. You’ll get a bunch of files required to run the program.
Double-click/Run LGFlashTool2014.exe file to Open LG Flash Tool.If it doesn’t open, install Visual C++ Runtime Library from here and then try again.
Boot your LG device into Download Mode:
Power off your LG device
Press and hold Volume Up button.
Connect your device to PC with a USBcable while holding the Volume Up button.
Now load the .kdzfirmware file into LG Flash Tool window on your PC. Click the Browse button at the end of the “Select KDZ file” line. Leave every other option as is in the LG Flash Tool window
Once you’ve selected .kdz firmware file, click “CSE Flash” button to proceed on flashing the.KDZ firmware to your LG device.
Normal Flash” button doesn’t wipe data and the “CSE Flash” button wipes data. If you’re upgrading from a stock firmware, then “Normal Flash” might do.
You’ll get a “Read Phone Information” window, it will be blank for the most part. Just hit the START button and proceed.
Now you’ll see “Select Country & Language” window. Select “Different” from the country list and then “English” from the language list. And remember to NOT tick the Smartphone upgrade checkbox, it’s for Windows Mobile phones, not your LG device running on Android
You’ll see a progress bar now. Just wait until it’s 100%, after which you might get an error “Connection to server failed”. This is okay. DON’T disconnect your phone at this point
firmware update progress on your phone. Once it’s complete, your phone will automatically reboot.
After flashing process starts and might take up to 5-10 minutes. So keep patience and wait