Remove spark plugs.
Remove rocker arms with pressure levers. If the rocker arms and camshafts are not renewed, then they must be installed again in the same place and in the same position, otherwise, on V8 engines, the main position of the hydraulic valve clearance compensators must be checked.
Pull the camshaft back or lift it together with the support post after loosening the fastening nuts. For M110 type engines (280S and 280SE) Camshafts are removed together with the camshaft housing. Or, unscrew the rear cover-plug, pull the camshafts back and then unscrew the camshaft housing.
Unscrew the hydraulic valve clearance compensators (V8 engine).
To remove the valves, you need a special tool for compressing the springs. If it is not available, then place the head with the interface on the workbench so that the desired valve is well supported at the bottom by the support surface. Next, place a piece of tubing slightly smaller than the valve spring cover on top of the valve cover and tap the cover down with a hammer. Cone halves (crackers) at the same time, they will pop out of the groove on the valve stem and fall inside the piece of tube. It is necessary to firmly hold the hammer on the tube so that the crackers do not fall out. Sequentially pull out all the parts of the valve stem and be careful not to lose any of them.