Take off the valve cover and turn each of the rocker arm shaft bolts slightly with the socket wrench till they are ready to be unscrewed by hand beginning with the outer ones. The bolts are immobilised on the rocker shaft. Next, remove the rocker arm and shaft assembly and remember the position of the rocker arms and washers and shaft retainer/spacers, if you have dislocated those. Removing the retainer/spacers: Use pliers to grasp the two wires on the retainer/spacers and this is by bending each up in a manner that they sit perpendicular to the shaft. Take out the pushrods and lay or place them orderly to allow easy fixing in their rightful places. Inspect each rocking arm for signs of wear, cracks or any defects on the ball socket pivots, and tips. Check for galling, stress cracks or any other signs of unusual wear on pivot seat and faces, also check the rocker arms for excessive wear or any other signs of having been compromised, replace any worn rocker arms and also fit new pivots or shafts where necessary. For shall mounted rocker arms, look out for galling and excessive wear of the shafts and plugging of the oil holes. Another place on the engine, which requires checking for cracks and signs of past bending, as well as the extent of wear at the ends, is the pushrods: they need rolling on a piece of plate glass. Apply clean engine oil or moly-base grease to the lower end of each pushrod and position then back into their original position, making sure that they are in the lifter socket. Grease moly-base on the extremities of the valve stems and the top end of push rods and on the rocker arm shaft. If removed, install the rocker arms, washers, shaft retainer/spacers and bolts in reverse order and then fasten the rocker arm assembly onto the cylinder head. Vary the turning of the bolts beginning at the centre in a progressive manner towards the required torque in order to accurately fix the provide the correct interface for the pushrods on the rocker arms. Last but not the least; you should then fit the valve covers.