It is very intricate and any mistakes could lead to serious damage to the engine. You should only try it if you are extremely experienced or consult a professional. Take out the timing cover, air intake resonator, brake vacuum pump, drive belt, thermostat housing, radiator hoses, heater hose, alternator
Crankshaft Pulley upper intake manifold and valve covers. Take care not to spoil the magnetic timing wheels on camshafts. Remove both up and down
Oil Pans. If necessary take off the timing cover and coolant outlet housing. Temporarily set up the crankshaft pulley bolt then bring together the timing marks on both crankshaft and camshaft sprockets. Check that the phaser marks are in line with plated links. Indicate direction of rotation for all chains. Press tensioner plungers then detach timing gear splash shield. Unbolt oil pump tensioner and sprocket. Put camshaft phaser lock tool between the phasers and loosen oil control valves. Remove phasers as well as timing chains. Inspect parts for wear or damage. Replace if need be. Tidy up units then fit new chains. Rotate crankshaft verifying alignment of marks. Install before doing this coolant housing together with water pump gaskets. Apply RTV sealant so as to have a proper installation of your Timing Cover. Tighten bolts on cover before finishing other installation steps. Fill engine with coolant or oil; start vehicle for leak testing.