First, go To this thread and download all attachments. Make sure shttps is C:\shttps
Next, you'll need FASTBOOT
First go to Start>Right-Click Computer>manage>device manager. When you connect your device with battery out, hold Vol + and plug in usb. You will need to be in Device manager to see something pop up under TI Omap4430 or something. Make sure to Right-click>update driver quickly, it will disappear fast. When you do this, navigate to [fastboot folder]\usb_drv_windows and select that folder for driver installation.
Now you can open up fastboot by Win+R>cmd>cd [your fastboot folder] and type "start.bat"[or whatever it's called maybe start_fastboot.bat] It should bring up a white window. Now you must do this:
in the fastboot window press 1 for fastboot it will say press enter, press enter, then it will say waiting for OMAP44xx device, plug in usb with no battery. Then it will say wait 5 el el el or whatever put battery in. next you will be in fastboot mode on phone[will look backwards and kinda messed up]. Now in device manager look for LG P2, update that driver with fastboot\usb_drv_windows
that will allow your computer to communicate with the unbrick offline flash kdz fix.
Cheers! Also make sure to flash the correct u-boot x-loader if you need to. If your phone came with ICS try that, if not try JB. Either way in fastboot you can just go back and forth until you find the right one.