After the intro, you will find that you are Princess Leia (or Chewbacca, if you choose) in front of Jabba's palace. Collect all of the studs, then collect one of them from the palace door. When you do, an eyeball droid will attack you. Shoot it with your blaster or bowcaster a few times to destroy it. Do the same for the other ones. When you shoot the last one, the door will open.
When you go in, you will find lots of gammorean guards there. Use Chewie to get through the gammoreans (he can kill a gammorean in one punch) and go into one of the side rooms. Pull a lever there to shut the door that the gammoreans are coming out of. Then do the same for the other room. Next, go into the room on the left and pull the other lever (not the one you shut the gammorean portal with). You will become a bounty hunter. Press the force button (levers button) to throw a thermal detonator. Move away from it when you throw it cause its gonna blow!! Sometimes thermal detonators detonate immidiately after you throw them. If you fire your blaster at the detonators they will explode. Sometimes they will lodge in things and blow them up. You can then collect the studs. Walk into the green circle by the door that is in the right side room and press the thermal detonator button. The door should open.Walk through and you will find Luke Skywalker battling more gammoreans. Kill all of the gammoreans,then you will need to backtrack and turn into a bounty hunter again. Walk up to the door and open it. Luckily, there's a new bounty hunter machine inside the door. First go against the right wall (as opposed to the left wall) and build two platforms. Jump on one while you are not Luke and he will force the platform. Walk along the narrow ledge and drop into a cage. The door will raise. Collect the studs, then finish killing the gammoreans. Turn off the tunnel that lets the gammoreans slide out and continue.