Download the stock nandroid and recovery from here:
optimusV_stock_nandroid_and_recovery.zip
Use 7-zip to extract the file, then place the boot.img file in your c:/
android-sdk-path/platform-tools/ folder.
Press your Windows Start key, then type
cmd and press
enter.
Type
cd c:/android-sdk-path/platform-tools
Boot your phone into recovery, then hook it up to your PC
In the cmd window type
adb shell
--If you get a # prompt, continue, if not, see below
Type
exit
Type
adb remount system
Type
adb push c:/android-sdk-path/platform-tools/boot.img /sdcard/boot.img
Type
adb shell (once again, be sure you have a # prompt, not a $ prompt)
Type
flash_image recovery boot.img
Type
reboot
If you haven't flashed a ROM previously, you should now be back to stock, though your home and menu keys may be swapped.
If you didn't see a # sign when you typed adb shell, try method two here, you will end up rooted, but stock.