Go on a little boat ride and access and hack the ctOS server.
Objective: Locate a guard with the access code
Get yourself a boat to the eastside of the ctOS control center. You’ll see a guard patrolling a building on the far right who has a hidden camera. Access it, the switch to the camera across the area on the left. You need to stop steering the boat as you can’t hack/access at the same time.
Scan the guards here to find the access code. You’re looking for a guy who’s on a wide patrol pattern so be patient and systematics to track him down.
Objective: Hack the ctOS server
Objective: Leave the area
Head further north on the boat to a fallen tree which is near the server location marked on your map. Pull he boat up under the tree and as close to the rocks as possible. Get off the boat and walk up to the cliff where the server is located.
There’s a guard here with a hidden camera, but just wait for him to turn around and sneak past him and the fenced area and through the doorway on the far side. Now being a hacking minigame.
You’re on a timer instantly with this one, so turn the timed point twice then the lower right point needs unlocking and turning once (so two clicks in total). Turn the top right point once, the middle point once and the timed point three times, unlocking the final point in the lower right giving access to the camera. Move the camera up and change to the one in the middle of the room providing access to the hacking point. Leave the same way you came in to finish the mission.