The Goods
Make your way into the city and then head left. Go through the building and then take cover when you get back outside. You'll start to be attacked by a mortar. You should still have your Markza from the previous area so try to use it to take out the Turret and mortar. When those are both down, start moving up a little ways. There will be more Grubs ahead but they shouldn't be anything special. When you get closer to the turret however, watch the building on the right because Diggers and Grubs will come out of it.
When you've dealt with them, enemies will start appearing across the street and running over to you. These include Diggers, Wretches, Grubs, and Ragers. Try to snipe the Ragers with your Markza and then take out any remaining enemies in more conventional methods. You should move away from the area with the Troikas however because after you finish that group, a Digger will come through the locked door behind you. He shouldn't be too tough on his own. Kill him and go through the door.
Enter and then exit the building. You'll find yourself on a higher level of the building. You'll be able to blow up a barrel which will knock the truck into the water. This will allow you to cross it safely. Enter the police department and you'll automatically pick up the explosives that you need before entering the garage.
In the garage, watch out for Tickers, they'll be scattered around. Grab ammo here and then go through the door ahead and to the right. In the next room, as you make your way to the back, you'll be attacked by a few small waves of Tickers. Fend them off and go through the door at the back left. There will be stairs here that will lead you to the next level up.
On this level, you'll have to contend with Grubs and Boomers at first. When you enter the next room, you'll also have to kill a few Raging Ragers. Exit the back of that room to get outside again. Follow this path along until it leads you to an alleyway between buildings. Follow the alleys but try to avoid the One-Shot. You'll follow this alley until it leads to a "street" (though the pavement is completely covered).
Sniper Alley
In this street, you'll need to avoid getting hit by the One-Shots as you make your way up. Start by going over to the right side and then shooting down the long tall pipe on the left side of the street. Aim for the top and shoot the barrels to knock it loose. This will allow you to cross the street back to the left. When you've done that, get inside the buildings and keep moving forward. You'll come across a Grub or two and a Digger (likely).
Kill them and then cross the street back to the right. You'll enter a building with Grubs and Diggers again. Look at the back of the room that you entered and you should see a counter with a back door behind it. The back door will have a Crimson Omen on it. Go behind the counter and you'll find stairs leading down. Go into the basement and you'll find the [COG Tags] against the left wall. Head through the building now and back over to the other side.
You'll have to go through a couple more close buildings before coming to a tall building with stairs leading up. Take the stairs up and you'll bump into Wretches and Grubs. The top floor will exit out to an area behind the One-Shots. Go around behind their position and take them out. With them dead, take one of the One-Shots and use it against the various Boomers coming at you. These Boomers will be accompanied by a group of Grubs.
When they are all dead, head into the first floor of the building through the large doors.
Setting Bombs
There are four columns here marked with bomb outlines. Set your bomb on one of them and the others will set their bombs as well. Check out the floor for ammo and weapons. You'll be attacked in this area so you want a Lancer and some sort of Shotgun if possible. Find one of the explosives and stand next to it. Hit the X button to use it and then a prompt will appear on screen. Wait for the shrinking circle to be in the highlighted section and then hit A. Do this three times to activate the bomb. If you get interrupted, you don't have to start from the beginning so if you have to stop and fight, do so.
As you start to prep the first bomb, you'll be attacked by Wretches but as you start to arm more bombs, Drones will spawn on the upper levels and start shooting at you. As long as you move quickly and are prepared to chainsaw Wretches as they approach, you'll likely not have much trouble setting the explosives.
When they are all set, you'll be attacked from outside. Get into position at the corner of the building and start shooting out through the new hole in the wall. Boomers and Theron will be your first enemies here but they'll be outside and the Theron will use Lancers so they shouldn't be too threatening. Keep an eye on the Boomers instead.
Work through this first set of enemies and more will start to show up including more Boomers, more Grubs, and two Reavers. Off to your right should be a One-Shot. Grab that and you can use it to take out the Reavers and Boomers in one hit. Finish up the Grubs and the chapter will finish itself.
