Go to the first pair of platforms. There will be three blocks floating in the air to the right of the platforms. Stand directly under the space to the left of the first block and jump. If done correctly, you should have made a block under that space. Then, stand directly under the second block and jump. If done correctly, you should have made another block right under the second block. Stand directly under the third block and jump. If done correctly you should have made another block right under the third block. Then, jump on to the third block that you have made then, jump to the second one you made. When you are on top of the second one you made, walk very slowly just by tapping Left to reach the edge, then jump. If done correctly you should have hit the second block that was already there, and a vine will spurt out. Climb to the top of the vine and then run to the end of the area where the vine leads you. You will be able to warp to world 6-1, 7-1, or 8-1.