What you need is the "Adaptive Camo" gear with the upgrade. Then you play the first High-Rise level "Listen and Learn".

1. Steal Key Card from the guy patroling
2. Go through the gate to the right
3. sneak past the second camera and go right to the helipad
4. use the camo the first time to get the bag
5. sneak back the way you came
6. use the camo at the second camera to get past the guard and camera
7. use the camo in the entrance area to get past camera and the two guards.

Do not wait around to long or the patrol routes will not fit. If you are quick about it you can do it in three minutes.