Go towards the stern of the skiff and fix a lever. Use it and you'll gain access to another ship. You'll be joined by Han and Chewie. Go to the bow and use the Force on the white bricks. That will make two levers appear - use them both and you'll be able to go further to the right. You now have to fight Boba Fett. When you defeat him, go further. Use the Force to pull the brown bricks out of the side of Jabba's barge to form a platform. Use it to jump to the right. Behind the grey curtains at the back you'll find two levers, use them both. Use the Force on the curtain furthest to the left to make a step for Luke - jump on it to reach the upper platform, then push down the crate. Build a grapple point. Use it to reach the third lever - you can now go further to the left. Open the two parts of the mechanism there. Use the Force to set the middle element of the right pattern to yellow, then use the turnstile to set the bottom one to blue. Enter the ship.
By destroying the machines on either side of the room you'll get some bricks that can be formed into a gun - use it to smash through the door. 3PO will join you now. Use the bricks to the left to build a panel for him. In order to turn it on, use the Force to grab the turbine from the right, then use the Force on some loose bricks to the left. As a droid use the panel and use the elevator.
Go right. Use the bricks to the left to form decks and a speaker, also use the Force on the spheres to the right. Use the hook on the grapple point. Once you're up there, build a crate and push it down. Now build a second speaker from the rubble. Use the Force on the spheres laying on the floor. Now stand on the highlighted circles on the floor until you complete the whole pattern. And let the disco begin.
Go forwards until you reach the deck. Destroy the blue box at the back and push it all the way to the rotating target in a force field. Now switch to 3PO and use the panel near the second target. Go to the right. As Luke access the hatch at the bottom of the screen and going under the floor move to the right, behind the grid. At the junction turn left and when you're up use the lever. Destroy the blue grid blocking another crate and push it outside. Also, use the brown bricks at the back. Move the box near the door that you formed, and you'll finally be able to go up.
Destroy the protections on the ladders on both sides of the deck and in the middle. Use the Force on all of them and you'll create a passage to the stern. As R2 use the panel to load the gun, then man it with another character and shoot the two rotating targets.