this a semi hard job, proceed with caution, the average time on this by a pro is 3 hours.
below are the instructions.
Drain off coolant and dispose of correctly.Installation: Vent cooling system and check for leaks, refer to Cooling System, Service and Repair,Remove vibration damper, refer to Harmonic Balancer.Remove thermostat housing refer to Cooling System
harmonic balancer removal
Unscrew and remove splash guard.Remove alternator drive belt, refer to Drive Belts, Mounts, Brackets and Accessories. Remove drive belt for a/c compressor, refer to Drive Belts, Mounts, Brackets and Accessories.
Note: If the drive belt is to be reused, mark direction of travel and reinstall drive belt in same direction of rotation.Remove fan coupling with fan wheel, refer to Cooling System.
removal of thermostat housing
Disconnect intake air manifold.Unscrew and remove splash guard.Unfasten drain plug for coolant on right engine block. Drain and dispose of coolant.Installation: Replace sealing ring. Tightening Torque, refer to Engine, Specifications. Top up coolant. Vent cooling system and check for leaks, refer to Cooling System.E38: (7 series) To improve accessibility to coolant manifold, lift water valve out of mounting and press to one side.