Alright, when you enter the level you will see a car crashed on the wall. Behind the car is a dead body. Next to the body is a nanokey which will open the entry doors.
When you're inside the building look around under the stairs. There should be an old rusty hatch which will lead you to a secret comuter room where you can change the satellites direction in order to send the message to chad.
Now you have to walk up to the top floor and search for a key which opens another hatch. The key can be found from the first cardbox thats on the shelf. This hatch will take you to the top of the building where you can send the message. There are multiple ways to leave the area safety but I will not spread that this time.