Cutler: Star Wars Episode IV: A New Hope

In the second act, Luke Skywalker (the contemplative hero) and Han Solo (the civic hero) dress up like Imperial Storm Troopers on the Death Star. Princess Leia is captured in the Death Star and is scheduled to be terminated. It will be very difficult to reach her to rescue her and Han does not want to rescue her. When Luke tells him that Leia will be killed, Han replies "better her than me" which indicates his selfishness and status as a civic hero. Luke tells Han that if they save Princess Leia, there is a large money incentive for him ("she's rich"). Han agrees and they rescue Leia.
This particular part of the film shows an obstacle for Luke, Han, and Leia. Luke wants to rescue Leia because she has the droids that hold the plans for the Death Star, equalling a shot at success for the Rebel Alliance. Leia is captured and the Empire plans to execute her. Han does not care about the Princess until Luke tells him that there will be a reward if they rescue her. He agrees and when they rescue her, he gets paid. However, towards the end of the film, he comes back to help Luke destroy the Death Star and becomes a Captain in the Rebel Alliance. Luke needs to rescue Leia because he is fighting for the Rebels and wants to destroy the Empire. He tells Han about the reward in hopes that he will agree to rescue her, which he does. Leia is trapped and relies on Luke to rescue her with Han Solo and Chewbacca.
This scene shows Han's initial transition from civic hero and smuggler who is just in it for the money to a contemplative hero and someone who wants to help the Rebels and his friends. While he agrees to rescue Leia only because of the money, he also agrees because he wants to help the Rebel Alliance. At the end, he is totally committed to the Alliance.