1) Reach the extraction zone
The official introduction to this mission is going to be very short and it will take about 30 seconds. This mission is going to start with a typical cut-scene (#1). You will see allied trucks heading towards a nearby base. You will have to wait for the game to transport you into one of the trucks. The second vehicle is going to be destroyed in just a few seconds (#2).
Your vehicle isn't going to be entirely destroyed, so you'll survive the attack, however you will have to wait for the main character to regain consciousness (#1). Once this is done, you will have a few seconds to organize your team (#2). As you've probably noticed, you will be issuing commands to one of the members of the Ghost team, as well as a small group of allied units.
1a) Clear the roadblock (Your main objective here will be to disable a roadblock which has been placed in the central section of the map. This is going to be the only passageway leading to an allied base, so you won't have any choice.)
I would recommend that you IMMEDIATELY hide your men behind available objects, because there are some rebel forces heading here from the east. Your allies should hide behind a destroyed truck (#1). As for the member of the Ghost team, you should move him to your left. Start firing at the enemy units (#2), however your men may be able to take of this problem without your assistance.
Start moving east (#1). I would recommend that you secure the entire map with the help from your team member, so you won't have to waste too much time giving orders to allied soldiers. The second group of rebel units can be found near a larger hill (#2). You will have to place your teammate correctly, so he'll be able to cover this entire area.
There's also a possibility that one of the attacked rebel soldiers manages to survive. He would probably hide behind one of the lower buildings (#1). As a result, you would have to kill him before moving on any further. Keep heading east. Make sure that you and your colleague cover this entire area (#2), so you won't go past anyone along the way.
Now you will have to start moving towards a nearby road. It's going to be located to the north-east (#1). I'm sure that you won't have any problems finding it. BEFORE you proceed any further, you will have to kill a single rebel unit. He is hiding inside a small building to the south-east (#2). Make sure that you don't lose any health points here.
You should be able to spot some rebel units in the distance (#1). I'd strongly recommend attacking them from here, because you will be exposed to their attacks and you wouldn't have anywhere to hide. Once they're gone, order your team member to hide behind an opened gate (#2). He shouldn't have any problems following your orders.
You should consider approaching the metal gate as well, because you will be able to take out a few additional rebel soldiers from here (#1). Make sure that the area has been secured. Check the second screen (#2), because that's where you'll need to go. Save your game here. It's important, because you will be dealing with a lot of well hidden enemy soldiers.