Continue forth to reach interior of the rig. You'll then have to make your way to the gas mask lockers to protect yourself from the imulsion. More lambent mutants will attack as you proceed to the gas mask locker. So stay together and kill them before they get close. Once you've reached the locker, the checkpoint will be triggered.
Go downstairs to the lower floor and navigate the passable paths until you reach the stairs. You'll encounter a few lambent mutants along the way, but not that threatening enough to be wary of. Continue upstairs until you find a closed door that you need to open. Before opening it, there's a hatch to the left that you can kick open. Clear the room of lambents and you'll find the COG tag in the corner of the room.
M. Blythe, SGT, Kinnerlake
Exit the room and don't return to the objective point yet. At the end of the hallway is another corridor which will take you to a heavy weapons locker, according to Paduk. Enter the first room and activate the switch there. Exit the room through the other door and use the ladder down. Open the next door to get outside. You'll encounter dark wretches her so take them out and go downstairs.
There are scattered weapons in the area so you may want to exchange/ replenish your ammo before activating the flare. Examine the flare launcher to proceed. Wait a bit and locusts will start attacking. Hold your position and fend off the enemy attack wave.
Stay in cover as you deal with Reavers and more lambents. Keep defending your position until the evac raven arrives. Once it lands, run to the helipad to to end the section.