How do I ‘unlike’ a Facebook page after I have liked it?

I joined the Facebook group called “Newcastle, ONTARIO” because it’s a neighbouring community that I am interested in and thought, way to go Heather Rivers http://www.facebook.com/profile.php?id=72611711 for creating the group, and for gathering two other administrators Tom Lynn and Sophia Grey http://www.facebook.com/profile.php?id=100001777989432 and that the group had tons of promise and would be awesome from Newcastle and Durham Region. I see I was in good company because when I went there today