Follow this tutorial but use this firmware instead of the one they link to:
Working Firmware Link: http://files.persona.cc/zefie/files/cell/LGLS670/roms/LGUpdater/cab/LS670ZVC_11.SC_11.P60674.cab...
Something must have messed up for me, I follow every step exactly and after rebooting I can no longer get into bootloader mode and it wont boot into android, help!! It's just a black screen!