Before we can take of the rocker arm cover off the cylinder head you will need to first loosen the rocker arm bolts on the front side of the cylinder head. In case only the pushrods are to be withdrawn, the rocker arms should be rotated in order to elevate them. When it is safe to do so take out the bolts, the rocker arms, as well as the pivot balls and keep them in separate containers with different labels so as to facilitate identification of the original position of the bolts that go back to the cylinder heads. Lift the pushrods separately, by unscrewing the rocker arm bolt and then pulling the pushrods up ; place them in a perforated cardboard box also marked 'front of engine' to avoid confusion. If the pushrod guides are to be removed then, it would be useful, to make a mark to position the component correctly. Check all the rocker arms for signs of weariness, cracks or damages especially where the rocker arm sits on the push rod and the valve stem, make sure that the hole at the end of the push rod is not blocked. Inspect the valve end of each rocker arm and force the rocker arm to either end of the damage zone and replace the rocker arm along with pivot balls. Check the shims and bushings for visible signs of wear and warpage of the pushrods: roll them along a piece of plate glass. For reassembly, coat the lower ends of the pushrods with clean engine oil or moly-base grease and position them back to their right places that is, back into the lifter socket until they seat properly. It is recommended that moly-base grease is applied on the ends of the valve stem and the upper of the push rods prior to the placement of the rocker arms coupled by the installation of the bolt. Erect the rocker arms, fit the pivot balls and bolts and sliding the moly-base grease to the pivot balls before building engine oil pressure to protect the mating area before making the specified torque.