Turn around and grab the rope at the back of the ship. Watch as you crash through the window for an epic kill. Pick up the Assault Rifle and use the wall for cover. Pick off any remaining opposition. Loot the room to refresh your health, armor, and ammo. Proceed through the hole in the wall on the left side of the building. Cut the chain on the scaffolding and proceed to the next one. Cut that chain leap across the gap to the balcony.
Each room on the way to the ground level will have exploding tanks of gas. Use these to take down the soldiers and conserve your ammo. Dispatch anyone in the first room and head downstairs, clearing out that area, as well. Once it's clear, a helicopter will be outside the window. Take it out with the Rocket Launcher on your Assault Rifle or the 'Shoot' mode on your Laserkraftwerk.
On the level just below where you fought the helicopter is another piece to add to the Laserkraftwerk. It's up a small ramp in the corner of the room. Loot the area and start heading down. Each floor will have guards, so take them out with the aid of nearby flammable gas tanks. Head out onto some scaffolding and follow it down to a lift, which will put you on the ground.
BOSS FIGHT - THE LONDON MONITOR:
Use the underground tunnels for cover and charge your Laserkraftwerk along the way. If the London Monitor starts firing at you, get into the tunnels and take cover. If the London Monitor's core turns from a blue metallic tint to an orange or red tint, start firing at it with your Laserkraftwerk. As soon as you shoot the core, the London Monitor will fire its missile pods at you. Fire at the pods as soon as they open before ducking into the tunnels to charge your Laserkraftwerk. Repeat the process until all six pods are destroyed. The next phase of the battle begins. Run underneath the London Monitor, avoiding the fire and wait for the hatch to open and expose the engine. Fire your Laserkraftwerk into the engine, repeating the process until the London Monitor is no more.