Melee an enemy so they fly off the side of the ship in "Armada."

Mission 12: Armada

After the initial sequence with the jammers at the start, you will head through the ship. Eventually you will come outside again and you will see a couple of enemies near some crates, as well as a sheer drop of the edge of the ship. Quickly run over to this side of the ship, and you will see an enemy fire a zipline down from above. Now, that enemy will slide down the zipline and land pretty much on the edge of the ship. Once he lands all you need to do is press [ Register or Signin to view external links. ] to melee him off the edge of the ship. The trophy will unlock shortly afterwards. For a visual walkthrough, refer to the video below.