At the entrance of the stairs or behind

the bunker next to the enemy machine gun position shooting how many can kill as many as possible
After a while there will be teammates to blow up the bunker the first is easier to solve the second distance is farther away and not only a direction of the enemy and the sky is dark need to be careful. The second machine gun position is also blown up after killing a target apartment building where the threat is greater enemies and then while looking for cover while rushing up kill downstairs and wait for teammates to throw a grenade to the house to blow up the enemy after going in. The house is recommended to use shotgun it does not matter but I think this is more atmosphere. After killing all the enemies go outside and rendezvous with friendly troops and get into a Humvee to go to the next battle site.