To the right of the statue of the sword piercing the ground, and below the Motor Forge. Where you can jump the open area to the four heads carved into the mountain side. You'll find a group of rock statues of hands giving the "Metal Horns" jester out of the ground. The biggest one has steps leading up to it. Go on that platform, hit Y, and you can change what head is carved into the mountain side. Make all 4 the guy with the goggles. Pretty simple.