The USB is inserted into the TV, and the TV is powered on (sometimes while holding the physical Power button) to trigger the automatic firmware flash.
You may find listings on Software Zone which specifically mentions the P130-338 V6.0 USB-updatable firmware. How it is Used Download P130 338 PAL ATV LSC320AN02 rar
LSC320AN02 . This is a 32-inch Samsung-manufactured panel commonly used in budget or mid-range LED TVs. The USB is inserted into the TV, and
PAL ATV stands for the analog tuner system (Phase Alternating Line) and indicates this is the standard TV software version rather than a digital-only variant. Download P130 338 PAL ATV LSC320AN02 rar