So you want to flash new firmwares on your L7 or downgrade firmware for rooting?
Here is quick tut showing you how it can be done in less than 20 mins
First of all you will need few things:
a)Install "B2CAppSetup.exe" and run LGMobile update.
a)Connect your phone to PC with USB "debug" mode enabled and wait for drivers to install.
b)Install msxml.msi (Right click on file and select Install)
c)Turn "windows enabler.exe" and switch to the "ON" position( left click on icon)
Start "UpTestEX_mod2_marwin.exe", select your KDZ file.
Set emeregency, 3gQCT as pictured and press "NORMALL WEB UPGRADE TEST"
NOTE: Do it on your own risk