Halo: The Master Chief Collection - Halo 2 - Enchanted - Halo 2: Activate Terminal 6 on Delta Halo. This achievement is fairly easy to unlock.
On the mission Delta Halo, near the start of the mission, run past the first area of enemies and continue on the path. Run past the jackal snipers and you will see the building where the bridge controls are located.
Inside of the building where the bridge controls are the terminal is on the wall to the left.
Run over and interact with it and your achievement should pop! Enjoy!