Out Of Shanghai
Enter the warehouse up ahead and move through to the doorways at the other end. Cross into the adjacent warehouse, take cover behind the large crate by the hangar door to your right and start picking off the soldiers outside. Remain behind cover and eliminate these soldiers as the pop out from cover to fire. Several of these soldiers may try to move in closer to your position. If this is the case, you can blindfire at them by pressing RT/R1 while behind cover without holding LT/L1. Blindfiring works best with a shotgun, such as the Buqiang 300BP used by the army.
There are a ton of soldiers here, so remain behind cover until you're certain the area is clear. You can move outside and take cover there if the troops' numbers are dwindling. Either way, your goal is to make it to the warehouse at the other end of the yard.
Once you've dealt with the first batch of troops, scour the area for weapons and ammo before entering the next warehouse. The Buqiang 800 rifle will come in handy in the next area. This weapon has an ammo cap of 15, but is very accurate and ideal for taking out key enemies. One of the soldiers you took out must have been wielding a Buqiang 800, so press down on the D-pad to locate one then swap a weapon for it.
Blindfire when an enemy gets too close to your cover.
Turn right once inside the warehouse and grab the fire extinguisher by the third doorway before heading outside. Outside, duck behind the cover near the third doorway and position yourself at the top corner. Then, equip the Buqiang 800 rifle and aim north. A large group of soldiers, including two armed with machine guns, will soon appear.
There will be distance markers pointing to each of the machine gunners. You must take down these guys quickly, as their weapons will tear you to shreds otherwise. As soon as the first machine gunner comes into view, fire your Buqiang 800 rifle at him to quickly put him down. Target the second machine gunner when he appears and do the same.
Once both machine gunners are down, pick up the acetylene tank or one of the fuel cans by your cover and throw it toward the soldiers covering on the other side of the warehouse. Shoot the fuel can or acetylene tank when it reaches the soldiers and you'll end up detonating the fuel cans behind their cover as well, making short work of them.
Taking down the machine gunners
Several of the remaining soldiers may attempt to close in on your cover. Hang back with your rifle and pick them off as they approach. You especially need to keep an eye on the stacked crates to your left, as there is sure to be a lone soldier covering there at some point. Use any fuel cans near your cover to dispatch the remaining enemies in the warehouse.
When the warehouse is clear of enemies, move out from cover and step outside. Press down on the D-pad to locate both of the machine guns dropped by the fallen soldiers and pick up both for extra ammo. There are sure to be more soldiers outside, so take cover behind the stack of skids and gun them down.
Clean up the remaining soldiers with your machine gun and then sprint to the other end of the alley. When you reach the ruined wall, drop down to the train yard, sprint across the tracks and open the door on the other side to move into the next area.
Sprint behind the two trains and take cover behind the crates along the second train. There are two gas tanks on a trolley in the doorway you can target to dispatch a couple of the enemies there. Other than that, hang back with your machine gun and put down the rest of the enemies in the station. The game will auto-save once you've completely cleared the station of enemies, so mop up with your machine gun before moving outside.
Watch out for the sniper in the train yard.
Take cover behind the pillar to the right of the train car up ahead. A wave of soldiers will appear, so shred them with your machine gun and then push forward. Take cover behind one of the pillars in front of the row of train cars and look for a sniper on top of the structure at the other end of the area. A distance marker will be pointing to this sniper. Crouch behind the pillar and continuously fire at the sniper until he falls.
Cross to the cement cover by the tracks once the sniper is down. Some more soldiers will appear by the train cars across the tracks. There are a couple of red gas tanks on a trolley on the right side of the platform you can target to hopefully kill off one or two of these enemies. Push forward to the open train car once you've dealt with these enemies and take cover inside. Yet another batch of soldiers will appear on this side of the tracks; put them down before crossing the tracks and opening the door at the other end.
Once you're through the door, hold LT/L1, slowly move out of the train car and gun down the soldier on top of the second car. Then, exit the car and take cover behind one of the stacks of crates along the side of it. Put down the soldiers covering in the distance and then move forward.
Enter the open train car when you come to it and pick up one of the acetylene tanks inside. A train is starting up in the distance and you must catch it before it leaves. There are several soldiers between here and there, so you'll have to quickly clear them out and then make a mad dash for the train.
Get to the train before it pulls away.
There's no need to kill every soldier here; just enough so you can make it to the train without being gunned down. Throw the acetylene tank you're holding and shoot it to clear out a couple of the soldiers. Target the two red gas tanks on the trolley by the train car to your right if any of the soldiers are moving into the cover on the platform there. There's another acetylene tank in the train car you can use if things are still sticky.
When the train starts to pull away, sprint out of the train car and make a beeline for the caboose to trigger a cutscene and complete the chapter.
Catching the train