The goal of your first shot is to break down the first gate without setting off the alarm. Launch at the gate.
Power Activation Point
Shoot out your lasers anytime before you hit the gate, however, be careful not to set off the alarm as the alarm will put down the gate behind the first.
First Shot Result
You should be able to push out one of the metal bar. The metal bar will destroy the pile of 5 pigs in the back.
Launch your second shot with similar path. It does not have to be exact as the key is on your power use.
Second Power Activation Point
After you pass the wind blower, use your power to pull on top of the gate.
Second Shot Result
The pieces that you have pulled kill all the pigs being chained at the top. They would fall on the switch and open up the gate.
Aim and launch your final bird. Now you can either go between the gap and hit darth vader directly, or if you miss you can use your jedi power to push on the metal bar which gets to the darth vader pig.
Third Power Activation Point
Use your power depending on where you have landed.
Third Shot Result
The metal bar falls down and kill the rest of the pigs. You will then earn the honor of three star master for the stage.