Get around 40 Red Pikmin and take them to a ledge where you find a pellet with a "5" on it. Press the C-STICK to launch them quicker onto the ledge. Once all the Pikmin are on there, look for a pool of water with a root going from the land into the water. Walk up the root onto the land and avoid the Spotty Bolborb. Call your Pikmin to kill it and then grab the part. Note: Take the Bolborb back to the Onion if you have extra Pikmin.