It should be behind the left exhaust manifold above the starter. You might need to remove the starter to gain easy access. Disconnect the battery. Remove the worn plug into the sensor. Remove the bolt that is holding the sensor. You may have to wiggle the sensor at the base a bit as you pull it out. Replace with new and make sure it is pushed in all of the way. Replace the bolt, wire plug, starter (if was removed) and reconnect the battery.