From the start, follow the left wall around until you can see a door with a green light above it on the opposite side of the courtyard, make your way here and turn to the right, you will need to kill all of the locust down below you on the landing platform. Kill the drones here until the reaver shows up, if you can destroy this, then a king raven will come in and destroy the remaining locust ground forces here. Continue further along the ramparts here and take the first left, behind a tower here on the ground is collectible (1/2). Pick it up and continue on to the next landing platform.
As you arrive, you will see a helicopter take off and explode just prior to grappling locust forces start jumping up onto the platform. Attack them as per normal, and soon enough a reaver will come in to land on the platform melt its face off with whatever weapon you have handy and polish off the remaining drones in the area. As you do, Anya will inform you of your next objective. Follow the squad into the next area that looks kind of like a parking garage. On the very left side of the room in an alcove is some ammo, grenades and a cover mounted mulcher. Grab it if you like and head to the railing overlooking the courtyard below on the opposite side of the room.
Drones will come into the area from the street to your left and from the garage doors directly across and below you. After a short while a boomer or two will come to join them, so remember to take cover on 'Boom!' or you are going to regret it. After the boomer is down, drones will continue to pour into the area from both entry points and will call in a pair of reavers to spice things up a bit. Attack them if you wish, but shortly thereafter a helicopter will come and finish them off anyway, along with the remaining forces below.
Once again Anya will come through on the radio and tell you where to go next. After she does, a platform will extend, giving you access to second floor of the structure on the other side of the courtyard. Continue up the stairs at the back of the room and wait for the colonel chump to open the door. As he does, continue up the next flight of stairs, take a left down the hallway and man the turret in front of you, next to the column shoot down the reavers attacking the building above you until Fenix tells control that he is moving to the main gate.
Continue out the opposite side of the room from the entrance and turn right into a small room. Wait for the colonel to open the gate and mosey on through. Continue down the spiral stairs here to a raised platform overlooking the street in front of the north gate. Pick up the mortar here and go nuts. There is also a cover mounted mulcher if you continue along this platform a little ways to the left and if you follow the platform to the very right, you will find collectible (2/2). Head back and focus on taking out the waves of drones as they come into the area. After you kill a bunch of them, a boomer and a grinder will arrive. Take them down quickly and then prepare yourself for a pair of brumaks. One will enter from straight in front of you, and another will come into the area from the right.
Focus on killing one at a time, focusing fire on their faces and guns with just about anything to take them down. If you still have not used the mortars or cover mounted mulcher, now would be a good opportunity to do so! Once the brumaks are dead, the chapter is complete.
