Hello internet,
Very simple achievement if you dont get distracted from the main story like me. Just play the MAIN story and the achievement will unlock after the mission wildlife preservation.
i have found no solution for imported characters other than joining another player while he is doing his main missions, continuing the story missions on the game mode you left off or making a new character and play the story again. (just dont get distracted by all the DLC)
if you downvote please let me know why so i can add anything you miss.