i have just tried to change the spark plugs on my fiesta.when i looked at them they were full of rust it was that bad icould not get the socket on to the plug. it looks like they have not been changed for years as i have only had the car for 1 month.i chipped all the rust away so i can get the socket on and put some penertrating oil around each plug. but when i tried to take them out 2 snapped .leaving half the plug still in with the thread still in the block.anyone got any ideas how to get them out.will a easy out work i do not whant to take the head off help please