Once you gain control, turn right at the intersection and kill the man who walks through the door. Go through the door and into the warehouse. There will be a couple of men in the main room that you need to take out quickly. Head out the shutter at the back left and then round the corner in the alley to find two enemies. Shoot for the enemy on the right and a squad mate will take out the other.
Head through the doors that require the wire cutters and then up the stairs. There will be three men spread over the next few rooms but they shouldn't pose any threat as long as you take your time. Head up another floor and watch as a friendly takes out two enemies in the next room. Hop out the window and down to the street outside. Move up the street in front of you. Move up this street on the right side. It'll be fairly easy to clear the left side but watch for group of enemies just ahead on the right by a truck and car. A grenade will likely take a few of them out.
Open the truck at the end of the parking lot to find nothing. Then turn around and head into the alley on the left. There will be quite a few enemies here but take your time and just use the corner of the brick wall for cover. Head up to the intersection, turn right and enter the building on the left. Kill the few enemies here and head out the other side of the building. Hop down once you get outside and then turn left. You'll have to fight your way up this street. Watch out for exploding barrels.
If you can make it close to the end and take cover, a chopper will come and clear out the group of enemies that comes from the left. Head to the left and use the large objects for cover. Push forward and down into the parking garage to find a truck. Jump into the truck and enjoy the vehicle segment. Shoot the enemies on the train when you get a chance, just to be on the safe side but I'm not entirely sure it has any effect on this segment. After this you'll end up on your feet again.
When you are back in control, follow Wall croft through the trains and onto the platform. There will be two enemies on the platform at the intersection. Turn left at the intersection and move up the middle, peaking out to take pot shots. Kill the enemies up ahead and then turn right at the end of the tunnel. Go through the door and you'll start approaching the exit of the subway but there will be plenty of enemies and not a whole lot of cover so use the corners for cover. Wrap around the wall to the left and go upstairs. Watch for the enemies at the top.
At the top, watch the snack counter to the right, you'll find a good number of enemies there. Clear those and the enemies to the left, then head up the stairs to the gates. There will be a few enemies up the hall fleeing. Kill them and follow them up the hall. At the intersection, turn right and climb out of the subway. Make your way over to the group. Wait for the truck to come around and open fire until it tips over.
