You can now make your way to the ctOS Control Center and head to one of the many gated entrances, each with their own entry strategy.
The main gate can be hacked, but the guard directly behind it can spot you if you try to enter, so head right and hack the control panel near a smaller mesh door to get inside without a fuss. While easy to get inside, you start out on a lower level with no height advantage over the guards.
Take the construction ramp that leads up to the fencing and climb the boxes to get a good overview of the whole area. This gives you easy access to the cameras to get a good layout of the area.
There is a guard directly behind the main gate, so instead of opening the gate go around the right side and use the blocks to climb up behind the yellow and black barrier. This gives you a height advantage on most of the guards and access to few different objects to hack for distractions and better views of the area.
The south side of the area can only be entered through the windows, which are guarded by one man with a hidden camera. You can face him and hack into his hidden camera to see what the Profiler says about you. Unfortunately, without some advanced skills and special weapons to reduce the sound of shooting glass you will likely find this entry unfruitful.
Cunning Route - Using the Cameras
Without even entering the center you can access any camera and move from camera to camera, marking all the guards, until you enter the building. Spot the man that can call for reinforcements and then access the camera in the center of the room. The man leaning against a bunch of pallets smoking has the access code for you to hack without ever entering the grounds.
In order to advance, you will want to aim your camera toward the man with the hidden camera. The object is to distract him to make him walk away from the window and then hack into his camera. This will get you to the access point you are looking for.
Stealth Route - Melee it Up
Using the many distractions like forklifts, car alarms, and explosions (though these draw attention to other guards) you can make your way into the center and quietly take out the guards as you go. This allows for the most XP, but also puts Aiden at risk. That being said, there are two easy kills that can be performed without any risk to Aiden by hacking the crane holding a large container in the air. This will kill two guards, provided one was not distracted, and provide extra coverage as you progress into the area.
Aggressive Route - Pull Out Your Gun
You bought that new gun for a reason, so pull it out and go on a rampage killing everyone in your path. It isn’t the best idea, but you will get reinforcements called for added experience.
Once you have the access code, either by getting it through the cameras or by taking out the guards, head for the southeast corner of the upstairs interior level. On the wall, near a phone you can hack to attract one of the previous guards is a control panel you can hack. This is the first time you will deal with hacking an access point, which is basically a small puzzle.
Your objective is to get the blue beam to the lock at the end of each puzzle to advance to the next puzzle and eventually into the server room. As the first access point you should have very little problems, simply start from the bottom of each puzzle and work the beam up or around to the top. When you reach the final puzzle you will notice that one of the switches is red. This means that once you turn it you will have a limited amount of time before it turns back. Simply turn it to make the beam go right and then complete the puzzle quickly to access the server room.
Inside the server room take the time to hack the three video logs, though they are not part of the game’s collectibles, and then hack the main server to complete the mission.