In order to gain access to the Pack-a-Punch Machine, the player must first turn on the power. Once done, there are three parts around the map to a boat engine that need to be collected in order to travel to Turtle Island. The locations of the parts are as followed:
In the Mess Hall, leaning on the pole in the center of the room, next to a trash can.
In the room where Tuff 'Nuff is located in the cabin, to the right of the bunks when entering the room.
In the Recreation Area, leaning again the booth below the camper near the entrance to the Old Marvin Mine.
Once the parts have been collected, head over to the boat launch at the White Tail Beach. There, the boat will be ready for use. Before going onto the boat, there is a film reel to the left of the entrance of the building where the boat is. Pick up the reel and board the boat. The boat will take the player to Turtle Island, where a broken film projector can be found in the cabin. Outside of the cabin by the zipline is another film reel. Pick it up and with the two film reels, insert them into the projector, causing a portal to the Projector Room to open up, where the player can Pack-a-Punch their weapons. Pack-a-Punching a weapon will award the player the achievement.