Tried searching through the site for this and couldn't find it. Is there a thread out there that gives instructions on changing out plugs in an 02 deville? I popped the cover off the front bank today and could see them sitting down in the rubber tubes, but didn't want to do any damage so thought better of going any farther. Do those rubber tubes come out, do I have to pull the valve cover to get at them? Any tricks to this?