Explore the Floor Achievement in Halo: The Master Chief Collection

By this point in the game, you should be familiar with Hunters in both their appearance and their general combative behavior. During the mission, Shutdown, you will eventually reach a large Forerunner chasm that has several platforms filled with enemies. On the other side of the chasm, there is an energy lift that must be taken in order to reach the next portion of the mission. On this final platform, a duo of Hunters will greet you.

Once you reach this area, kill one of the Hunters. With the second Hunter alive, you will want to trick him into charging off the side of the platform. This can be done by standing at the edge and allowing the Hunter to charge straight at you. Right before he hits you jump up and utilize your jet pack to hover in the air right over him. If timed correctly, the Hunter will have little time to stop the momentum of his attack and run right off the platform, thus unlocking the achievement.