The removal and replacement of camshafts require many specialized tools. The intake camshaft is removed by first removing the Valvetronic intermediate levers, turning the eccentric shaft while at the same time removing the oil spray nozzle. Removal of VANOS adjustment units should also be carried out. Then, carefully remove guide blocks, return springs and Valvetronic intermediate levers in a laid order respectively. Remove bearing caps together with guide blocks followed by intermediate levers. Next, the camshaft may be lifted out and then compression rings as well as rocker arms are to be taken off it. In order to take out exhaust camshaft, there must be dismantling of upper and lower camshaft bearing castings first. Both camshafts should be inspected for wear or damage before being installed down into their place on cylinder head again.To fix intake camshaft hydraulic adjusters and rocker arms must be installed; after that lubricate it and put it up with cylinder 1 lobe in top position (up). Install camshaft bearing caps before placing intermediate levers back into its place followed by guide blocks after them.This should be done along with installation of tension springs on special appliances so as to stretch them properly while tightening retaining bolts slightly downwards.The oil spray nozzle should also fit into position perfectly well.Slightly open up exhaust valves of cylinder no2 during installing process on this case, put back exhaust camshaft together with bearing castings aligning as well fastening holding screws correctly.Finally, install VANOS adjustment units.