First, you will need to unlock the Carmina (boat/plane) awarded after completing the mission “The Great Escape”. Head to the northern most dock, and spawn the vehicle. Once inside, take it to a cliff’s edge that leads to water; preferably the one in the video.
Although this is a boat, it can drive on land as well, so position yourself towards the cliff’s edge, get a running start, and fly off, holding down on the left analog stick, easily grabbing at least 100m, and unlocking the achievement.