The latest firmware for ATT LG-P870 LG Escape is “P87020d” as of 04/22/2013.
How to upgrade my ATT LG-P870 LG Escape to latest firmware?
You can use use the LG mobile Support tool to install the firmware update.
Need the Stock Firmware to recover your LG P870? Here you are:
What is .KDZ file?
KDZ is the LG format for ROMs which is the built in read only memory that hold the instructions for the phone to run the hardware and features.
Need to download the LG USB Drivers for your LG P870. Here you are the latest LG USB Drivers for mobile phones Ver. 3.8.1