Sometimes you just need to relax and take the weight off your shoulders.
In order to relax and take the weight off your soldiers you must play as Ms. Fortune, use her head removal move, and leave it off for about 1 hour. Start off by going to Help & Options then Settings. Make sure you set the time to Infinite, this will allow you to stay idle as long as you need for the achievement, Sparring Mode also yields infinite time if you prefer that instead.
Next, go into Local Versus Mode and select Ms. Fortune. Press + or or to remove her head and after that just simply sit there with her head off for about an hour. This is a cumulativeachievement so you don't necessarily have to unlock it in one sitting, but it is faster.
Leave Ms. Fortune's head off for about an hour or more and this will unlock once you've met the necessary time. If you're going to leave it idle and not be present, it is recommended that you use a wired controller for this to avoid your game falling asleep on you, resulting in the pause menu coming up, halting the process for this achievement.