At the start of this section, you'll immediately see the Declassify skull. If you accept it, you'll encounter Lancer-wielding drones in this section.
Kick the door open and immediately take cover to avoid getting shredded by the machine gun ahead. Take out the enemies here, including some maulers. There's also a COG tag in the middle of the room, a bit to the front of the machine gun emplacement.
Finish off the remaining enemies to complete the section.