you need to unbolt the 4 bolts from the rocker assembly from whatever position that lifter is under. make sure the valves are closed. if open and you try to bolt it down, the threads in the head will pull out rather than the rocker bolt down and open the valve. watch the shims between the rocker and valve, they stick to the rocker and fall off and if you lose 1, there's 2 different sizes. good luck, chuck.