The player starts by talking to Mr. House, after completing The House Always Wins VI. He will explain, and the quest begins.
Once you arrive at the substation an NCR trooper will approach you, telling you to keep out. Ignore this and enter the garage door. Wearing NCR armor means they will not open fire.
Once inside, head for the right-hand side of the building, access the terminal and insert the chip. Exit the substation, and report back to Mr. House.