Clean the area around the where the wires connect to the spark plug to avoid any dirt or foreign stuff getting into
the hole when you remove the plug. I sometimes use a soft brush and blow the dust out or compressed air.
Be sure to mark the wires so that you'll know to replace them on the correct cylinder.
Holding the plug wire firmly by the neck at the plug base, and gently remove the wire so as not to break it's internal
Otherwise, you'll be making another trip to get new wires. If your wires are old and cracked etc., you
may want to replace them anyway.
Using the socket wrench, remove the plugs and check them for color and deposits.
Black deposits mean your engine could have problems or is running too rich.
White plugs deposits mean the engine is too lean.
Light gray or tan deposits are OK.