(!SPOILER WARNING FOR THE MAIN STORY!)
This achievement can easily be acquired while playing the games campaign normally. To get this achievement, simply complete the mission Bury the Hatchet.
As soon as the mission is complete, you should be awarded with the achievement!
(READ THIS!) There have been some reports that the achievement sometimes glitches and doesn't unlock the first time if you play the beginning as Trevor, I suggest that you start this mission as Michael just to be safe.