You will be needing the driver and softwares (KM555.7z). download it here-->
http://www.mediafire.com/?66xmw1dm752jd71 .Extract file you have downloaded (KM555.7z) in your desktop.
.Open KM555 folder cut "UpTestEX_1.0.4.8" and "FlashUSB_1.0.0.7" Folder and Paste it on your Desktop.
.On your desktop you will have your three folders (UpTestEX_1.0.4.8 , FlashUSB_1.0.0.7 and KM555 folder)
.Paste these three folders on your drive C together with your desired KDZ file. (you will see download link in the firmware section of this forum)
.Open KM555 folder and run/install "LGUSBModemDriver_WHQL_ML_Ver_4.9.7_All_Win7.exe"
.Open "FlashUSBAGOLD" folder and run/install "setup.exe"
.Do same process on "FlashUSB" folder. Open it and Install "Setup.exe"
.After that back to you drive C open "FlashUSB_1.0.0.7>WIN32" folder (I'm using 32bit) and run/install "setup.exe"
.Connect your phone (you must select PC suite as USB connection mode) on your phone.
.Open LG drive on My Computer and Run "USBAutoRun.exe" to install your phone driver and PC suite. you can download or use the provided CD.
.After installing Open your PC suite Installed and you will see your phone is connected. (You have installed this to make sure your phone is connected). You Can Exit PC suite. (File>Exit) Do not Disconnect your Phone.
.Open your Drive C. Open "UpTestEX_1.0.4.8" > "UpTestEX_1.0.4.8" folder.
.Run "Windows Enabler.exe". You will see a new icon on your Notification Area/Tray (lower right, together with the time).
.Click on it to turn it on. (You cannot proceed on the next procedure if is is turned off)
.Back to "UpTestEX_1.0.4.8" folder. Run "UpTestEX.exe". A new window will appear (R&D Test Tool).
.On the Upper Left on the new window click on "INFINENON". Just click on it.
.On the Upper right Click "Model" and type KM555.
.Click on "select kdz file" and browse your kdz file on drive C.
.Click on "Loop Test count " and type 1.
.Click "Start Upgrade" twice.
.wait
.wait
.wait
.wait
.wait
.wait
.wait
.You Will see Finish or something like that on the lower right of the R&D Test Tool window. A Sign that your done!
Congartz! You have just broke your Phone!
Joking ;D ;D ;D
You can now disconnect and open your phone (it's turned off)
Enjoy your Upgraded phone!
You can view this video for your reference-->
By the way, you don't need to remove your battery, sim and memory card. no setting will be changed.
Whew!