Kill stormtroopers, which are guarding this place and enter inside. You will be have to defeat there the red guard, but if you will use Force Repulse (L2+O) and your lightsaber this will be quite easy.
Take the holocron from the trophy room and approach to the shining door. This will trigger a cutscene in which Starkiller meets Princess Leia. Leia is asking Starkiller to destroy Skyhook - device, which (as she suppose) will be used to transport wookie's on the orbit. This device is commanded by captain Ozzik Sturn.
You are about to explore the prison sector of the complex. In first hut, which you will see when you will leave the rocky tunnel is located holocron (Force Power Sphere). Before you will be able to take him, you will have to eliminate the sniper.
Release also all spotted wookies. They are closed in metal containers. When you will free them, they will attack Imperials. Just ahead of the prison gate (on her right side) is standing container. Inside of him, you will find hidden holocron.
Few meters from this place, in the hut behind the gate you will find another one. Take him and jump on the middle pale which is supporting the construction and take another cube. When you do this, enter inside the prison.
The prison corridor is full of the prisoners. To free them, bend the bars with Force. To shut down energy shields, which are blocking the pass, target the plug of the supply cable and tear her out.
In one of the cells, which is guarded by the droids interrogating prisoners, you can find another holocron (Force Talent Sphere). Next cube is located just ahead exit from this section.
It's time for the Leia's objective. Look on the trunk. At his right side, you will find holocron (Purple Light Saber Crystal). Take him and approach to Skyhook. This device is guarded by ordinary stormtroopers, laser cannon, snipers and Purge Troopers. First, kill the stormtroopers. After that, eliminate the laser cannon and snipers. During a fight with stormtroopers, try to eliminate Purge's with Force Lightning.
After cleaning an area from enemies, it will be time for destroying Skyhook. To do this, you have to slip off with Force six energetic spigots, which are located around the construction. Between spigots you will find the holocron. Take him. When you will slip off second spigot on the scene will inbound AT-ST piloted by Ozzik Sturn.
The fight with AT-ST is quite easy. It will be enough if you will be throwing in him rocks and containers. Remember to keep safe distance. Ozzik is rather slow, so even if he will target you, you will be able to evade his attack.
You can also fight in short distance. This is more dangerous option. As always you should use the combination: jump, few slashes and Force Lightning.