pretty easy ,punch small hole in plug,screw a decent size woodscrew in and remove usink a claw hammer.not technical but u dont want the old ones anyway.lightly! clean up core hole and drift new one in using a suitable sized socket.should be a tight fit.if not seal first with a setting instant gasket,red or green hylomar or similar.basicaly any method to get them out is good as long as u dont damage the manifold.REFILL WITH ANTIFREEZE.it has corrosion inhibitors
caine, June 2008