Dawn/Walkthrough

This is Your 7 am Morning Call
Once you exit the cryo tube and retrieve Cortana, you should retrieve a pistol you can find on the floor, near the left of the room. Proceed through the level to the elevator. Open it, and enter the shaft. Hold up left stick to move upward, and when the chief glances to the side, jink the left stick in that direction. Procede upward while dodging debris to get up the shaft. At the top, you are engaged by an Elite with an energy sword. Follow the button commands (melee) and hurl him down the elevator shaft. Continue until you are outside the observation deck. You will see an elite several yards directly ahead on a slightly raised platform at a console with his back to you. Charge him, get an assassination or beat down, and use your pistol or assault rifle to finish off the Grunts below you on either side of the room. Cortana will tell you to hit a button on the console that the Elite was fiddling with, but first, stock up on ammunition. There are several ammo crates in the room, mostly close below you. Fill up your pistol, stock up on grenades, and swap your Assault Rifle for a Plasma Pistol. After you've prepared yourself, hit the button on the console. Soon after, two phantoms will flank you and place two boarding craft on the windows. Frag the areas where the covenant jump out, kill the grunts with headshots, and EMP the Elites' shields with your PP before killing them with your Magnum as well. After clearing the area, follow Cortana's waypoint to the elevator.

In Space, No One Can Hear You Scream
Once you exit the airlock, immediately swap a Battle Rifle for your Magnum. Start sniping any Covenant you see, but be wary of the Beam Rifle-toting Jackals. Also, a forewarning, the Needler can now supercombine on YOU, so if you see anyone with it, kill them. Don't worry about the cruiser reaching you before you fire the missile, you have all the time in the world. As you clear out enemies, move around the wrecked walkway when it is safe to do so. It may be tempting to jump in and kill any remaining enemies, but you'll just end up signing your death warrent. Be careful of the Elites, though. Be prepared with plasma grenades, and a charged Plasma Pistol, should you need them. As you progress around the perimeter of the ship, always be on the lookout for any remaining enemies. When you get up to the missile controls, you'll see a Jackal and an Elite. Try and stick a grenade onto the Elite. Failing that, use a Plasma Pistol to drain his shields, then nail him in the face with a Battle Rifle round. As for the Jackal, just shoot him in the face. Now, activate the missile controls. Immediately after doing so, SPRINT towards the missile that's emerging. If you manage not to get caught in a missile battery or a Covenant Supply Depot, you should reach the blast door before the Covenant's boots even touch the ship.

Through the Fire
RUN. The Gravity Well won't affect you, but look where you walk, because it affects the scenery, and you don't want the last thing you see to be a Covenant antennae array. Get to the airlock on your right. As you enter, wait for the room to pressurize. Then run like crazy through the halls. Don't bother killing any Covenant, the ship will do that for you. Just keep sprinting towards any waypoints you see. Once you see the Elite limping down the hallway, you've almost made it. Turn left to reach a sealed door. Mind the Grunts don't shoot you. Then open the door.