Go to the place with the arcade. Click the arcade. As your Woogi is walking to the arcade, display the map and jump to the science lab. If you keep going to the right you will end up in the arcade, in the room that has been blocked by a red rope.
Go to Woogi Market. Buy some feet and hands. Go to your house and put yourself in the outfits. Take off the feet and hands then sell them. Go back to your house and put on your outfits. You will now be just a head.