The Truck Ride
Once here, three more enemies will come at you and back up as much as you can before taking them down. clear the room and head on to a room where there's a wrecking ball in the in the center. Go NW and notice the control area for the wrecking pall. Drop down and run to the control room avoiding the enemies. Once there, make Ashley operate the wrecking ball and she'll wreck this wall to piece and you hold off attacks from two entrances. When the wall is cleared run to the opened gate and leave the enemies behind you.
The next area is clean so explore it and when you hear mousic get to the back of the room and wait for your enemies. Once done, get to the main hall and enter through the formerly locked right door and head south. More music means more enemies. Activate a power to a shutter in the enarby room and make Ashley crawl under to open it for you. There's a save point here. Leave Ashley to one side of the doorway and approach the opposite site to operate the locks.Wait for the red lights to hit the center then unlock the door. Leave there and get into the back of a large tractor driver by Ashley, hold off attacks while she drives. There's a large truck coming at you, use the shotgun to blast it to pieces and keep one holding off enemies until the truck stops at a large lift.
Back to Basics
Get out and up the ladder. Be careful of enemies - then flip the lever and run back to the truck to save Ashley. Once it reaches the top of the lift, more enemies will appear a truck will come at you head on. Once you're off the tractor ride, collect items and use the merchant there.
Go up to the next door way and pick at your enemies again. Now go on south to take the lift to an upper platform causing a cutscene. Keep an eye out for events and stay alert. When its done, climb down the ladder and into the next hall. This white hall has laser so watch for the gaps and run between them. Activate the switch and unlock it - carefully dodging the beams and getting through to the door. In this next room, a lift will bring you down the next area where it's another empty place with a merchant and items as well as a save point. Keep going to where the red beacon is. Don't bother fighting it off yes but merely getting off the dangerous set of cargo containers.
Train Rides
3 locked cargo containers that need to have two different switches on them pressed. Do that and run to the door and get on the next container. Destroy the green locks to get to where the switches are. The first container's lock are right next to the shutters in front of the switch, hit it and run to the second where the lights are mounted high on the the beams. Shoot them down and run to the third where the first switch is visible and the second requires you to run through the passage in the center and turn left at the tunnel's end. Shoot the green lock that you see, backtrack to the west end of the cargo and hit the switch to open the gate.
Put some distance between you and the monster and start running. Use the explosive barrels and then switch to heavy weaponry. Time your shots well and shoot at the monster just as it starts moving to you. Keep firing at it until it burrows underground wherein next you have to dodge servral attack. Keep fighting until it eventually. When you're done, move on east.