After getting to know the Rusty Hooks for a bit, the player can find out that he can challenge the current leader (in this case, Kyle) to a fight (unarmed only) and whoever wins becomes the new leader of the Rusty Hooks.
The one caveat of the current leader is that he may choose anyone to be his "champion," and Kyle will always choose his favorite super mutant, Bear. After the challenge, the fight begins. Good luck! If the player wins the fight, he is the new leader of the Rusty Hooks. However, Kyle might be so pissed after Bear losing the fight that he triggers Bear's heart bomb – hopefully the player is not too close.