How?

All of Rudy's female friends would always tell him what a jerk his brother was, but he looked up to his brother, Jim, and just couldn't believe it. In particular, Rudy's girlfriend, Joy, would try to explain this to him, but he wouldn't listen. Finally, Joy found a magic spell to swap bodies with Rudy, so that he could experience his brother's pigheadedness firsthand. In Joy's body, Rudy couldn't believe what sort of jerk his brother was! He attended a party in her body, and Jim spent the entire night making passes at him! Jim thought he was hitting on his brother's girlfriend, which bothered Rudy to no end. He knew he'd have to tell him everything and get him to change his ways, but how?