1. Open the hood of your 1999 Chrysler Concorde.
2. Locate the engine cover, which is usually made of plastic and is located at the top of the engine.
3. Remove the engine cover.
4. You will see the cylinder heads, which are the cylinder-shaped components at the top of the engine. There will be three spark plug wires connected to each cylinder head.
5. The spark plugs are located at the end of the spark plug wires.
Replacing the Spark Plugs:
1. Disconnect the spark plug wires by pulling them straight up off of the spark plugs.
2. Use a spark plug wrench to loosen and remove the spark plugs.
3. Install the new spark plugs by hand, then tighten them using the spark plug wrench.
4. Reconnect the spark plug wires.
5. Replace the engine cover.
