Remove the intake manifold. See: Intake Manifold Service and Repair
Remove the A/C line at the oil level indicator tube bracket nut.
Remove the A/C bracket bolt from the engine lift hook.
Position the A/C line out of the way.
Remove the engine lift bracket.
Disconnect the ignition control module electrical connectors.
Loosen the ignition control module bolts.
Remove the ignition control module.
Disconnect the engine electrical harness housing from the camshaft cover (1) taking care not to damage the clips that hold the housing in place.
Disconnect the fuel injection harness electrical connector.
Loosen and remove the camshaft cover bolts.
Remove the camshaft cover.
Clean and inspect the camshaft cover.
Since you provided no engine size, I guessed at 6 cylinder.
It is not a diy job in my opinion as it is pretty involved.