First clear out the Spotty Bolborbs along with their infants. Gather 30 Red Pikmin and kill the beetle, then built the ramps and knock down the wall. You’ll need 50 Pikmin to carry the part. Next, there’ll be another door with ramps and a wall. Build the ramp and knock the wall down. If you haven’t done so yet, blow up the wall leading to your ship. Make your Pikmin grab the part and they should be safe.