This can also be done while sitting on any body of water. During the tutorial with the wingsuit, you are prompted to press while on the ground to launch yourself into the air. This trophy is earned by launching yourself into the air using the Bavarium Wingsuit from a body of water. Use the Bavarium Wingsuit to take off from water. Look at the Sly Fox Edited Apby Terminator You last step will be to clean up any of the couple misc trophies you might not have earned previously while playing the story or challenges.
If you didn't earn Stock-Keeping previously somehow you will almost certainly earn it here as one of the challenges involves killing drones. They aren't overly difficult or long compared to the ones from the main game, so if you earned the platinum previously these shouldn't give you much trouble. Your next step will be to complete the 4 wingsuit challenges that are included with this DLC. Along your way you might very well earn the misc trophies without trying. This consists of three missions and two sets of liberation targets that are required to progress after the first and second mission. Your first step for the DLC will just be to play through the story. The DLC is short overall with the story itself only taking an hour or so to complete, with challenges to do afterword to unlock upgrades for the new wingsuit. This expansion brings with it some new story missions and challenges, along with a couple new drop items and the most interesting item of all, a rocket powered Wingsuit modification. Welcome to Sky Fortress, the first DLC Expansion for Just Cause 3.