This is quite a long level, but you'll eventually be forced to pick up a laser designator for drone strikes from Captain Price. Afterwards, you'll go on the roof at shoot enemies on the scaffolding, do not use your laser on them, but instead shoot them.
Eventually a civilian car will roll up to you, and then leave. After that, 3 pickup trucks will enter the area one by one. Use your laser to paint the area you want to drone strike, and destroy the trucks. Keep in mind the missile takes 1-2 seconds before hitting. After the first 3, some enemies will attack along the left side and you want to focus on them before the 4th and final truck arrives. Use the laser on this last truck and make sure to destroy all 4 in 4 drone strikes to unlock this.
Possible on any difficulty, but recruit is probably recommended to make it as easy as possible.