Important safety tip
Be carefull removing the spark plug wires. If this is the first time they are taken off the plugs they may not come off the plugs easly. Make sure you pull the boot, not the wire. Twisting the boot first may not loosen it, it may not loosen at the top of the spark plug cause the contact can turn on its own. And you can't buy just one, they only come is sets. And they do sell a handy tool to take them off. I think loosening the plug wires should be part of the regular maintance.