Instructions
Walk up to the three Pikmin in the ground as soon as the stage begins. Pluck them from the ground by pressing the "2" button on the Wii remote. This brings your total Pikmin to six.
Run to the edge of the platform, and fall off. As soon as you fall, press "Up" and "1" together to grab the ledge.
Hang from the ledge as long as possible. From here, the other fighters can't attack your Pikmin. When Olimar pulls himself up onto the ledge, fall back off and hang from the ledge again.
Continue doing this as the Pikmin's flowers bloom. After about 40 seconds, all six of the Pikmin have bloomed flowers, and you win the event.