Workers' Compensation Achievement in Halo: The Master Chief Collection

This achievement can be earned in a solo Firefight match.

In the pre-game lobby, tinker your settings so that you are invulnerable and start the match with a Gravity Hammer and Concussion Rifle. Next, change the map to Courtyard, the difficulty to Easy, and the game type to Gruntpocalypse. Now you can start the game. When you spawn, simply run toward the right-hand side of the map and you should see a forklift. Your goal is to smack the forklift with the Gravity Hammer so that it splatters one of the many Grunts in the area. Even if/when the forklift explodes and is inoperable, you should still be able to toss it around with your weapons. It may take a few tries, but once you've splattered a Grunt with the forklift, the achievement will unlock.