U just take the plastic surroundings off so u can get to it.. then with your key on ACC , push in the little pin on top and it will slide out.
Make sure you have the new barrel with key in it on ACC when you put it in.
YEs you will need new keys.. but if u have central locking, who cares. Usually if u go to a wreckers u can get the barrel, and the 3 other locks for a 22 for about $50 if that.