// Set the controller radius to 0.3
var controller : CharacterController;
controller = GetComponent(CharacterController);
controller.radius = 0.3;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public CharacterController controller;
void Awake() {
controller = GetComponent<CharacterController>();
controller.radius = 0.3F;
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public controller as CharacterController

def Awake():
controller = GetComponent[of CharacterController]()
controller.radius = 0.3F