I tried to remove the plus previously, but even leaving WD40 in the well overnight they refused to unscrew. I don't want to apply too much force with the socket wrench in case I break the plugs.
Maybe I will leave them until I have to next visit a dealer!
I wouldn't leave it Clock, they aren't going to get any better or easier to come out with time. Tim is right about wd40, I've had more luck with letting some diesel sit around them, it creeps. If you get some movement, work them back in before applying too much force to wind them out. Hope it goes ok.