City of Danger includes Chewbacca. In the end part open the gate go use a book dude, open the door and you are in Mos Eisle. Use a small dude and go in the small passage brake brake Chewbacca should appear.
Free the Slaves includes Princess Leia. Go to the slave area and go to the low part and brake the metal use the solider passage - you found Leia.
Desert Ambush has R2-D2. Go to the first go to the top and whip the crane R2-D2 Whoop.