Angry Birds Star Wars Bonus Level #4 (S-4) is unlocked by accumulating 190 stars through gameplay in Star Wars. Once you have accomplished this task, you will be prompted and can either navigate directly to the level or access it via the Bonus Episode. Time your shot with R2-D2 straight ahead, blasting the center TNT. This will send stones into the other TNT and pop all pigs on the righthand side.
Go back to the Complete Star Wars Golden Droids & Bonus Level Guide. If you have a different strategy feel free to leave a comment below; however, don't just post your score via the comments, as that's what the leaderboards are for.