Get 35 to 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 faster on the ledge. Once all the Pikmin are on there, you should see 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 Pikimin, attack the beast, and kill it. You should now see the part. Have your Pikmin grab the part. Note: If you have extra Pikmin you can take the Bolborb back to the Onion to gain Pikmin.