OK, the problem: On a 1998 Opel (Vauxhall) Astra g, 1.6 litre, 8 valve, I cannot remove three of the four spark plugs, which seem to be stuck solid! I have no idea how long they've been in there and no idea what idiot put them in so tight! The fourth one was removed end of last year, by a mechanic who was not happy about the possibility of snapping it! What I need, is your help in getting them out, without (a) breaking them and (b) stripping the engine down! So any suggestions will be greatly received!