To change spark plugs on a 1994 Toyota Camry, remove the black shafts. The spark plugs are down the four holes. Use a socket set with extension to reach the spark plugs. Replace old spark plugs with new ones.
To change the spark plugs on a Vauxhall Zafira open the hood of the vehicle. The spark plugs will be located on the engine. It is best to used a spark plug removed to unscrew the plugs. They will be connected to a cable. Remove the cable. Replace the plugs with new ones and reattach the cable.