Get debriefed on the mission and then talk to Morgan. He will give you stuff you need for your squad. Now go to the terminals and choose what you want your squad to be. You need to use both terminals before you can leave. Once out head to your right to pick up your guns and ammo. Now head to the North west toward to the goal that says destroy two fuel tanks. Once there plant explosives on 2 of the tanks to finish that part of the quest. After you will be warped back to the mission briefing room. Choose another command set at the terminals and get ready to go. [personally I chose the Fire equipment because it was easier] Once that's done head to the Listening post and be careful there are a ton of guys and a lot of them have rockets so watch out. Once you make your way through the train track and through a broken building you will come to stairs. Climb those stairs and entering the building once inside follow the path all the way through and at the top killing everyone you see. Once at the top you will clear this part of the quest and be taken back to the mission briefing room where the achievement will unlock.