Go to the Steel Palace and kill the Emperor (who actually is a supercomputer) by formatting it.
Enter the Steel Palace and enter the room behind the throne room and use Repair to disable the force field. Interact with the supercomputer and hack into it (neither password option is correct). Under the diagnostics menu, select the option to format the machine and confirm the action. Then, return to AHS-9 for your reward.
Alternatively, since AHS-9 is not aware that the Emperor is actually a computer, killing Ken Lee will suffice to complete the quest.
Regardless of which of the two options is chosen, almost everyone in San Francisco will become hostile.