I am writing this now, as i flashed wrong recovery and was stuck at LG logo in my optimus pro device !!
By following the steps below, i was able to get back my phone exactly how it was before (without loosing anythin)
things you need
KDZ updater : Google It
Original LG OPtimus pro Firmware: http://csmg.lgmobile.com:9002/swdata...00/V10H_00.kdz
Go to the folder where you have downloaded the Firmware Updater : KDZ_firmware_updater and extract it. Install msxml.msi
Disable the Lg Virtual modem in device manager. Its under Modems
Boot up your phone in Emergency Mode by RETURN+VOL UP+POWER.
Its like bright yellow with Emergency mode written
run KDZ_FW_UPD.exe. and connect your phone (emergency mode) via usb.
In the window, select Type : 3GQCT Also select PhoneMode : DIAG
In the place where you have to give path for KDZ file, select the ROM you have downloaded using the link you made for your specific firmware
Hope it helps,