Tom: He said AC Delco, not Champion. Champions are great plugs for some vehicles (like my Jeep). AC Delcos are garbage in everything.

Return the AC Delcos and order some Bosch or NGK plugs from right on this site. You will be glad you did, and they all screw off (in fact I think they come unscrewed). I believe every AC-D plug has the terminal permanently attatched to the end.