First thing to do is take off the rods. Then, undo the little "keepers" that hold the lifters down to the engine block. Then cut away the green paint holding the lifter to the block. Next you need to make/obtain some sort of clamp that will tighten around the lifter stem above the engine deck while at the same time exerting pressure on the deck to force the lifter up and out of its hole. It is not a difficult operation, you just have to remember NOT to hammer down on the top of the lifter at any time - it can damage the cam face on the shaft.