I gather this is a yahoo group. If you are the moderator go into the member list. You will see a box to the right of each member. Check that box to prepare to remove the member. Then go up to the top and click the "Remove Selected". The member will be removed and sent a message.
go to http://groups.yahoo.com/group/bartonviewneighborhood ,click management, then members, find the member, click "edit membership" and look there.
members can also unsubscribe themselves. either by email to [email protected] , receiving a confirmation-reply and sending a (blank) reply to that - or by going to the aformentioned URL