Piece of piss Tiff.

Rocker cover off, rockers off, old tappets out, new tappets in, cover the lot in lubrication, rockers back in, clean the old gasket off the head/rocker cover, rocker cover back on with a new gasket. Don't forget the crossover pipe will have to come off to get the rocker cover off and I am not sure if the throttle body needs to be moved out of the way also.