I have successfully removed 3 of my 4 spark plugs, but the 4th one is proving to be a much more stubborn challenge. I have tried WD40 , cold engine, slightly warm engine, but no luck. I have been using a t bar wrench and I am possibly thinking, that I may get some joy with a socket wrench (if I can find the right size attachment for it). Has anybody got any suggestions/tricks/tips for getting a stuck plug out?