1. Locate the plastic engine cover: This is a large piece of plastic covering the top of the engine.
2. Remove the engine cover: There are usually clips or fasteners holding it in place.
3. Locate the spark plug wires: These are the wires leading from the distributor cap (if equipped; some variations might have coil-on-plug) to the spark plugs. Following these will lead you to the plugs themselves. They're usually in a fairly straightforward arrangement.
Important Note: A 1997 Achieva *could* have a different engine (though less likely). If it's not the standard 2.4L, the location might vary slightly. Consult a repair manual specific to your vehicle's VIN and engine code for the most accurate information. A Haynes or Chilton manual would be a good resource.