The DICS are on Alvarez's back, as they think he and Angel are working together. We need to blow up a police car and be chased by Alvarez himself to prove them wrong. First, you need to go and meet Gianna to pick up the detonator. Next, go to the police station to be able to plant it. Once you get there, head up the steps and take out the police officer inside.
You need to climb up the air conditioning unit at the back of the area and begin to scale your way up the building. On the next couple of levels (which you can pass by climbing more of the fan units) you will encounter a few more police before you reach the next waypoint. You will have to jump across the gap by sprinting just before you get to the waypoint, so look out for that.
Once across, you will have another guard in your way. Take him out as well as any others that have got a shot at you, then move up to the helicopter to plant the bomb.
Next, you need to place the detonator in full view so everyone knows it is you who did it. Jump back across the gap from before to place it where indicated. With that done, drop down, taking any enemies out, and exit the area, heading for the waypoint. Once you reach it, you will phone Alvarez, who gives you the all-clear to start driving so he can follow you.
Of course, as you have probably realized by now, we planted the bomb on the helicopter to blow up Alvarez himself, and used a DICS detonator to make it look like they were responsible - once he gets in, the helicopter explodes, taking care of that problem nicely.
You still have to escape the police, so use your normal evasion tactics to get away.
Reward: 15,000R$