go to the third pipe and go down, when you come out, the bad guys should be the little helmet dudes. Go to the pipe that is suspended in the air, about three away, and hit the invisible coin box to the left of it then go down that. When you come up there should be flying fish. Go down the first pipe after the first lava pit, I believe it's the third again, when you come out there should be a hammer throwing turtle, get past him and you're at the end, watch out for the fireballs jumping out of the pit behind the turtle.