In order to complete the Skull puzzle in the barn, you’ll need to open the upstairs Barn Tile Slider box to get a bone that can be found there. You’ll use that bone on the skulls to make sweet, sweet music.
Video of this puzzle can seen here: Skull Puzzle on Youtube
First, get the bone upstairs.
Then head over to the skull puzzle downstairs. Each skull belongs to a corresponding animal picture on the wall. In the picture below, colored lines show the skull that goes with each animal.
Use the bone from the box upstairs to tap on the proper skull’s left or right eye socket, depending on the direction the animal is facing.
If the animal is facing RIGHT, tap on the RIGHT eye socket.
If the animal is facing LEFT, tap on the LEFT eye socket.
The bone will break after the first row. Take it over to Grandma’s Regeneration Circle to repair it. Then complete the puzzle.
You’ll get the Skull Light Bottle as a reward and it will be used in the Windmill.