You start off in a small room. Head on to a nearby door. Open it carefully. There are some terrorists in the next room. Start shooting at them (#1). Remember to aim at their heads. Make sure you've killed all hostile units. Yezhov was being held in this room. He may join your team now (#2). You will have to escort him to the extraction site. I guess I don't have to remind you that he can't get shot. Otherwise you would have failed the mission.
Head on to the nearby stairs (#1). You should be able to reach a small marketplace area within a few seconds. DON'T shoot at the innocent civilians!! Their deaths would have jeopardized the whole mission. I would also recommend that you leave the rest of the team (including Yezhov) behind. Head on to the right wall. Start moving forward. You should be able to spot one of the first groups very soon (#2). Make sure you don't hit anyone else. You should also aim at the heads of your opponents.
The second group of terrorists will be located on your left (#1). Some of them will be hiding, so you must be very careful. Take your time and aim at the heads of the terrorists. Don't let any of them surprise you. The rest of the team may join you for a few seconds. Star moving towards the exit. You should be able to reach a small alley very shortly (#2). Leave the rest of the team behind. You should also reload your weapon.
Try getting closer to the entrance leading to a new building. There's going to be an explosion. Furthermore, new terrorists will appear in the area. Move back to the previous corridor and start shooting at them from the distance (#1). Thankfully, you should be able to score at least a few headshots. Make sure you've killed all terrorists. Head on to the new building with the rest of the team. You will find a new door here (#2). Before you decide to open it, make sure everyone's ready. I would also recommend that you leave Yezhov behind.
Open the door CAREFULLY. The area is crawling with enemy troops (#1). You have to be careful, though. There are also some civilians here. If you're lucky, you should be able to surprise most of the terrorists. One of them will be hiding amongst cars (#2).
You should be able to take out most of the terrorists on your own. Your teammate may join you now (#1). Nevertheless, you must be very careful. Some of the terrorists may still be hiding. Be sure to check the whole area! Start heading towards a nearby alley (#2). You will have to deal with few additional units. After that, rejoin with the rest of the team (including escorted Yezhov).
In order to reach the extraction zone you will have to enter a new building (#1). Thankfully, there aren't any soldiers inside, so you don't have to worry about that. Exit the building. You will come across a large group of terrorists (#2). Start shooting at the nearby soldiers, mostly because they pose a serious threat. You could also start throwing grenades at them, especially since you won't need them in the future.
Remember to leave the rest of the team behind! You will have to clear out the whole area on your own. Start moving towards the opposite end of this alley. Be sure to take care of the remaining units along the way (#1). That's not all. The opposite building is going to be guarded by at least 5-6 additional soldiers. I would recommend using the scope to take out most of them from a safe distance (#2).
Keep moving forward. You have to be very careful. There's a guy with a rocket launcher on your left (#1)!! You MUST take care of him quickly, before he sees you. This is VERY important. There's also a single sniper on the left balcony (#2). You should also take care of this problem. Since there are no additional units nearby, the rest of the team may join you now.
Use the nearby stairs. Start heading towards the main building. The entrance will be located on your left (#1). Use the stairs to get to the upper floor. There's a single terrorist here. Dispose of him quickly. Enter the room located on your right. It's going to be guarded by two additional soldiers (#2). Thankfully, you should be able to surprise at least one of them.
Step up closer to the designated zone. You will receive new objectives in a few seconds. An allied chopper is on its way. You will have to defend this area against terrorist attacks. Order your teammate to stay here (#1). He should already be standing by one of the windows, so he'll probably help you. The enemies will be coming from a nearby alley (#2). You CAN'T let them get closer to the occupied building! Once you've dealt with the first wave, be sure to reload your weapon.
You will have to deal with at least 2-3 additional waves. There's also a single sniper standing on a roof of the right building (#1). You should take him out as soon as possible. Some of the terrorists will probably get closer to the building. Use the stairs to get back to the ground floor. Stand by one of the windows and start shooting at the visible terrorists (#2). You might also consider throwing all of the remaining grenades at them.
An allied chooper should arrive here shortly (#1). You might want to observe its attacks, however this can be a little risky. Thankfully, you won't have to do anything else. This is the end of this mission (#2).