Disconnect the negative battery cable
Drain the engine coolant
Remove the engine covers and air intake components
Relieve fuel system pressure
Remove the intake manifold
Remove the throttle body and related hoses or connectors
Disconnect the wiring harnesses, vacuum lines, and sensors from the cylinder heads
Remove the ignition coils and spark plugs
Remove the exhaust manifolds from the cylinder heads
Remove the serpentine belt and any accessories blocking access
Remove the valve covers
Set the engine to top dead center on cylinder 1 if needed for timing reference
Remove the timing cover
Release timing chain tension and remove the timing components from the camshafts
Remove the camshafts if required for head removal
Remove the cylinder head bolts in the reverse order of the tightening sequence
Lift the cylinder heads from the engine block
Remove the old head gaskets
Clean the cylinder head and engine block mating surfaces
Inspect the heads and block for warping, cracks, or damage
Machine or replace the cylinder heads if needed
Install new head gaskets in the correct orientation
Position the cylinder heads onto the engine block
Install new cylinder head bolts
Tighten the head bolts in the specified sequence and stages to factory torque specifications
Reinstall the camshafts and timing components
Verify timing marks and timing chain alignment
Reinstall the timing cover
Reinstall the valve covers with new gaskets if needed
Reinstall the exhaust manifolds
Reinstall the spark plugs and ignition coils
Reinstall the intake manifold and throttle body
Reconnect all wiring harnesses, vacuum lines, hoses, and sensors
Reinstall the serpentine belt and accessories
Reinstall the air intake components and engine covers
Refill the cooling system with the correct coolant
Refill engine oil if it was drained
Reconnect the battery
Start the engine and check for leaks, misfires, overheating, and abnormal noises
Bleed the cooling system as required
Clear diagnostic trouble codes if present
Recheck coolant level, oil level, and fastener integrity after a test drive