Head to the restricted area. You have to find and disable all three security terminals. If you have a sniper rifle, you can start picking off the thugs from a distance, away from the restricted area. There's also an audio log you can intercept on top of some pipes to the north (Iraq 02).
After disabling all terminals, follow the data lines until you reach the ctOS tower location. There's another audio log found inside. (Iraq 01) Unlock the tower and leave the area afterward. After the phone call with Clara, the mission will be complete.