When the heist first starts head to the casino and reach the side door on the right side of the building. Before moving towards the door make sure you take out the camera above using your stun gun. Then proceed to unlock the door using the keypad and enter the casino through the staff door.
Once you're inside, you need to take out the metal detector fuse box and then silently take out the guard at the front desk using your suppressed weapon. After that go through the metal detector and to your left you will come across another camera.
Take this camera down using your stun gun. Quickly take out two guards to your left who will just be chatting with each other.
Make sure you and your friend are in sync and have already decided who will take which side. For instance, you can take out the left guard and your friend can take out the right one.
Just make sure you take the guards out at the same time. Once you've taken out the guards proceed through to the double doors ahead of you.
After you've gone through the double doors, take cover and wait for another guard to come. Wait for him to come close to you and then take him out as well. Follow down the hallway but before continuing, there will be another camera as soon as you enter the hallway where you killed the guard. Take the camera down, but make sure the previous camera is still online since multiple down cameras will cause the alarm to go off.
After taking down the guard and the camera continue down the hallway and take a right, where you will come across a keypad door which will lead to the stairs — however, you won't be able to access it from this side. You will need to go around it.
So continue to the next door and use your keypad device to unlock that door. Just make sure the guard has left the room before you do so. After that quickly use the EMP from your phone and enter this room, wait for the guard to come back and take him out with a headshot.
Continue quickly where the guard just came from and go all the way around, passing the elevator and not going into the elevator. Go to the stairway and use your keycard to open the door to the stairway.
While going down, make sure you pre-aim because as soon as you take the first turn, a guard will be approaching you. So you need to take him out quickly and silently before he gets the chance to shoot at you and alert the rest of the guards.
After taking him down, proceed towards the basement, but as you're going further you will come across another camera, disable it using your stun gun and then proceed.
Once you reach the basement level, go through the doors and note there is no need to bother with the guards to the left. Go right and towards the vault, but be aware that before entering the next door there is another camera right beside the doors.
So make sure the camera is facing away from you and then enter the doors. As you pass through the doors you will notice two guards at the desk, take them both out and there will be a camera to your left.
Be careful of this camera and take it out as well if you get the chance. Or else just avoid it and head towards the security room keypad door. Open the door, head inside and take out the guard inside. There will only be one guard inside the security room.
Once you're inside make sure you keep an eye out for another guard who will be patrolling right outside the security room where you just came in from. As soon as you see the guard approaching towards your area quickly take cover inside of the security room and wait for the guard to leave.
Once he leaves head to the mantrap entrance through the door and use your vault keycards simultaneously to open the mantrap door. Now head towards the vault.
Once you reach the vault use your vault lasers to drill it open. The trick here is to not over-heat your drill. Make sure you press the drilling button but release it in-between.
Release the drill button as soon as you see the heat gauge going up. As it does, release the button and it will come down, then you can continue drilling.
Repeat this process until all the locks are broken and enter the vault.
Once you're inside you need to be quick about everything. Firstly, when it comes time to do the fingerprint scanner hacking, the pattern that you will see on one door will be the same for all the doors that you hack inside.
So make sure when you match the first fingerprint scanner hack patterns, take a picture of the pattern using your real-life phone, and then when you hack the next door, you can quickly refer to the picture and choose the pattern. This will really help you save a lot of time.
After you're done looting, leave the vault as soon as the timer hits the 30-40 seconds mark. It is always safer to leave the vault around this time.
Once you leave the vault you will need to use your keycards simultaneously once again to open the door and head back to the same staff lobby where you came from. This time around, the guards will re-spawn.
When you reach the area, wait for a guard to pass by and as soon as he does, go through the double doors and take out the camera to your right. Once the camera is taken down, take out the guard at the desk and move forward. Then take out the guard who passed by you earlier.
Now proceed towards the exit but make sure as you are going through the set of double doors. Do not immediately cross the second set of double doors. Instead wait and check your minimap for the camera to turn its cone of vision away from your exit point.
As soon as the camera turns to the left or right, depending on what side of double doors you've chosen to go out of, exit out and head to the keypad door leading to the stairway where you came from initially.
As soon as you enter the stairway, before going up, take out the camera using your stun gun and then head to the top floor, back to the staff lobby area. Avoid all the guards and leave through the staff lobby exit door where you came in from, where the metal detectors are.
It is up to you whether you want to either sneak out of this area or go out fighting. We had to go out fighting from here since the body of a guard we killed earlier was discovered. But you can do it carefully and make sure that does not happen.
After you get out of the casino, head over to the casino race track and either go for your getaway vehicles and head to the sewers to lose the cops, or as soon as you get on the race track, stay on the right side of the track and when the end comes, go to the right and over the fence.
This will take you to the road. Get a pedestrian car and quickly head inside the sewer tunnel and lose the cops. Come out of the other end of the tunnel and head to your buyer to compete your heist successfully.
The screenshots of running on the race track below are from The Big Con approach but it will be the same escape strategy here as well if you do not want to follow the getaway vehicle strategy.
Here is a screenshot of us in our getaway vehicle, heading to the same sewer tunnels during the 'Silent & Sneaky' approach. Another important tip here is to make sure you and your friend are in the same car to make it easier for you both to escape the cops.
If you are unsure of the exact location of the sewer tunnel entrance then you can refer to the map below.
One very important thing to note is that you must not go near the casino after you come out of the other end of the sewer tunnel. If you do so you will get an instant 5 star wanted level.
So take a different route to the buyer if the GPS is directing you through the highway near the casino. Do not take that highway and set your own way point to the buyer.
By following these escape strategies and delivering the goods to your buyer, you'll have successfully completed the Silent & Sneaky Diamond Casino Heist.
