No Easy Way Out Achievement in Halo: The Master Chief Collection

Despite the achievement’s description leading players to believe that this mission must be completed with dying, that’s not the case at all. In fact, this achievement will unlock so long as you simply complete the initial objective of this mission. That objective is rather simple: Activate the two UNSC terminals and protect at least once of them from the dozen waves of Promethean enemies.

As a general note, this achievement is best done on Heroic with 1-3 other players. The extra firepower is great when picking off Watchers and Crawlers and facing off against Knights. Towards the end of this mission, the waves of enemies will begin to die down a little bit and you will be required to activate a new switch on the equipment on the central structure. Before doing this, make sure to kill the two Knights on the top level of this structure and any other Promethean enemies that spawn into the area after these Knights’ death.

Once the entire area is clear of enemies, you will unlock the achievement and can now proceed to activate the switch and continue with the mission's objective(s) as normal. Remember, you can die as many times as you want, as it does not void anything related to the achievement.