[header] How to change spark plugs [title] Figure out your spark plugs' location and size. [step] Almost all cars have spark plugs located in a row at the front of the engine (or possibly on the top depending on configuration). Some older v engines have spark plugs located to the sides of the engines. 
With a few exceptions, cars have one spark plug for each cylinder. [substeps] Make sure the engine is cool before you get started.