If you have the stealth suit for the tanker mission (which can be obtained by getting at least 60 dog tags in the tanker episode), start the tanker mission on very easy and go to one of the holds where the marines watch the commandant's speech. Equip the stealth suit and beat up on some of the marines. When a marine gets knocked over, it causes a domino effect where the marines around the one you knocked over can end up getting knocked over as well. At first, the marines will get up, look confused, and end up going back into position, but if you keep doing it enough, some the marines that get knocked over will eventually have stars on their heads. They'll be woken up by the surrounding marines fairly quickly, so you can repeat the process once they do until the achievement pops.