Star Wars: Battlefront II/Among the Ruins

Capture the forward command post
There's nothing strange about this objective. You start the game with 60 reinforcements, and first you must take the command post at the top of the stairs in front of you. The easiest way to do this is not to run ahead, but to walk at the same speed as your allies and use them as distractions while you run for the command post. Use a grenade to clear out the top of the stairs, and keep your crosshairs pointed down the hallway. You troops have your back.

Destroy the particle cannon turrets
Switch to an ARC trooper (the one with a rocket launcher) and fire one rocket at each of the turrets. You should be able to hit both of them from within about 3 meters of the command post. Aim at the base of the turret, because the top moves quite a bit.

Destroy the generators to power down the shields
By this time you should have the Jedi hero, Ki-Adi Mundi. Take advantage of his lightsaber and destroy the shield generators just behind each of the shields.

Capture the northwestern command post
Now you have to back-track a little bit. The command post you're looking for is near the first shield. It should be guarded by two or three units, no match for your lightsaber. Just hang out around there until the CP is taken.

Destroy the Energy Collector Core
There are two parts to this objective. First you have to destroy more shield generators. So sprint down the street towards the tower at the back of the map. The shield generators are towards the back of the tower, so run around and find them. Be careful not to ignore the MagnaGuard that is guarding one of them, his rockets pack a punch! Once you have destroyed two of the three generators, you can go inside and lay waste to their energy core. Again, watch out for the enemy units guarding it, this time it's a droideka.

Acquire the Power Crystals from the energy core
Here's a hint: whenever this game says "acquire," it means "pick up and return to your rear command post." So that's what you have to do. Pick up the Power Crystals (white glowing object on the ground in front of the collector core) and run back to your starting CP. If you still have Ki-Adi, remember that you cannot use your "fly" ability while you have the "flag" (objectives like this are treated as "capture the flag" levels by the game). If you have any normal soldier, just ignore all enemy units except AATs. Those things can do a lot of damage really fast, so it's advised that you hide behind something in the landscape if you meet one of them.