The "Rescue Agent 14" setup mission is a significant challenge within Act 3 of the Doomsday Heist. Success in this mission heavily relies on being well-stocked with snacks, armor, and utilizing essential vehicles like the Armored Kuruma and weapons like the minigun.
Before heading to the shipyard, ask your friend to sit with you in your Armored Kumara. It will make it much more convenient to go through this mission.
Head over to the shipyard and when you get there, you will immediately enter a gun fight. Take out all the enemies outside and then head inside the warehouse through the big north entrance.
Stay inside your vehicle and take out all the enemies. Once you've killed them all, head over to Agent 14 and a cut scene will play, showing AI Juggernauts appearing from the north entrance you entered from. Quickly take cover by the wooden planks on the left hand side and switch to your mini-gun.
The Juggernauts are going to be invisible so switch to your thermal vision (don't worry it will be available once the Juggernauts arrive) and take them out using your mini-gun. An essential tip here is that you need to stay behind the wooden planks and slightly move towards the edge, just enough so that you can see the Juggernauts and aim at them.
Another trick is that you will be able to shoot through the planks you're taking cover behind, and this way the Juggernauts will not shoot at you, since they cannot see you. Aim at their heads and shoot. They should die after 2-3 seconds. Be very careful not to go in front of them though, as they will insta-kill you and are extremely powerful.
