How EXACTLY do I solve this puzzle in Zelda Ocarina of Time?

In the Forest Temple, you have to shoot an arrow at the picture of the green poe to make the puzzle blocks drop down... Now, which one do I start with? Facing which wall? Some of the blocks don't allow me to push them all the way together; there's a remaining gap. EXACTLY, like, from step 1 to step 497594376976, how do I do this?!?!?!?!