Take the stairs and move forwards. Eliminate all enemies that will get in your way. You should reach the pagoda. After a short cut-scene, prepare for a co-op snipe. You need to shoot at a fuel container installed under the bridge. Note, that if you will wait with the shot, your target will flee and the mission status will change to "failed".
Now get back to the place where you started this assignment. Eliminate attackers and use the hovercraft. Sit behind the wheel and follow the river. Remember that your machine can be destroyed, so try to avoid RPG projectiles.
The route is simple and short - you'll see a large closed gate soon. Stop your hovercraft near it (on the right hand side) and get out of it. Now you have an occasion to buy something - you'll have to destroy a Chinook helicopter soon, so get yourself a Stinger or an RPG.
Take the stairs and move forward. There are a few guys here waiting for you. Find some cover and shoot them all.
Move on until you see a fuel tank placed behind some bars. Destroy it with a few bullets. A heavily armored enemy will intercept you. He's coming from the other side of the river, via the bridge. Order you buddy to shoot at him. From the small tower with the fuel tank you'll be able to shoot the guy in the back.
On the other side you'll find another, analogical fuel container. Destroy it too and get back to your hovercraft. The GPS will show a control panel on your way - use it to open the first gate.
Get to your vehicle and park in between the gates. The GPS will show you another control panel. When you use it, a Chinook helicopter will bring some enemy reinforcements. Use your rocket launcher to take it out (aim at the back of the machine) and earn extra ten thousand bucks. Now there's only one remaining panel to use. You'll find it near the second fuel tank. The second gate will open, so get back to you hovercraft.
There are no enemies on the route ahead. Leave your hovercraft at a small pier and get the land. The footbridge ahead leads to a Chinese village. Approach it; you'll see two guards chatting on the right. If you have a sniper rifle, you may perform a co-op snipe to take them both out without attracting enemy's attention. However, if you do not have a rifle, you need to do the job in an old-fashioned way. After finishing a few guys, more Chinook helicopters will carry reinforcements. Kill everyone trying to hunt you. When most of them will die, a cut-scene will start, presenting an explosion. Get to the that damaged place and enter the building through the hole in the gate, made by the bomb.
There's another gate inside, in front of you, This one requires opening. Do it to continue the mission. If you want, you may do some shopping. Note there's a laptop on one of the crates. Use it to earn extra money. Now open the gate on the left. Behind it, you'll find another pack of hostiles and a manned turret. Shoot the regular soldiers and flank the turret from the left. Now enter the building these guys were guarding. Clear the first floor.
Now get upstairs and finish the rest (you may use a lift located on your left, it'll allow you to appear behind the turret guarding the second floor).
Now you have to get to the top of the building. You can get on the damaged stairs by performing a step jump. Be careful, as there are a few enemies coming your way. Note also that the third floor is guarded by a well-armored guy.
There a railroad gate on the top of the building. Open it.
Once you get outside, pick up the riot shield and follow the railway track. You'll get to another gate, but before you it, you need to defeat another heavily armored enemy.
Opening the gate won't end with a success. To save your lives, Rios and Salem will start the only back-to-back action in this mission. Simply shoot at everyone attacking you. Once you end the maneuver, enter the opened building and shoot your way to the control panel.
Once you use it, take the footbridge to get to another building. Inside, you'll find another enemy and a lever. Use it to end the mission in China.