In the process of disassembling the engine to replace the bearing, one has to unscrew the valve covers, 
Timing Chain cover, remove the timing chains and the camshaft sprockets with their spacers, make sure not to confuse the sprockets labeled as RB-right bank and LB-left bank since they should be replaced in the identical manner. Regarding 5.4L 4V engines, apply pressure using a C-clamp on the secondary 
Timing Chain Tensioner so that you can fit pins to immobilize it before removal, do the same with the other cylinder head. The seat of the plunger is triggered by spring so be careful when putting the insertion tubing through the end of the assembly. Using the camshaft sprocket bolt and the large washer to immobilise the intake camshaft, shift both the camshaft sprockets and their spacers with the secondary chain. Check the thrust clearance of the camshaft(s) with the dial indicator and use new thrust plates and bearing caps if the clearance is beyond the standard limit. The camshaft journal caps extra design to indicate their location for correct installation on the camshaft caps cluster. Do not rotate the crankshaft in various directions with the timing chains removed to prevent valve-to-piston contact. Proceed and unwind the bearing cap bolts slowly, then turn the caps in as well as raise the camshaft off the cylinder head without swapping the parts. Externally, look for any scratches or wear on the cam lobes and bearing journals, and then, by means of micrometers, take measurements of the diameter of each camshaft journal, and camshaft lobe lift, and replace the camshaft if there are large variations. The check Plastigage for wear and clearance of each camshaft journal, clean the oil feed tube and reservoir of the timing chain tensioner before the installation of the cam caps. If lash adjusters or camshaft followers were removed, replace them in the same positions, use grease or camshaft installation lube on the camshaft lobe and bearing journals before placing the camshaft(s). Replace the lost camshaft caps and tighten the bolts gradually so as to ensure the camshafts are correctly positioned at TDC with the timing chain and cover reinstalled in a reverse process of what was used to remove them.