Grab at least three Yellow Pikmin and use their Bomb Rocks to brake the stone walls. After that brake the regular bridge to the left of the Pearly Clam Clamp. Then kill the pearly calm clamp with the ship part, with Blue Pikmin. Then after defeating it, then take the ship part to the S.S. Dolphin, this needs twenty Pikmin to carry it. Try to get this before the eighth day, because a mamuta or Goolix will appear on the tree stump after the eighth day.