Instructions
Level up the Pokemon to the required stage to learn Ancient Power naturally. Each Pokemon that acquires Ancient Power gets the move at a different experience level. For example, a Shieldon or Bastiodon will learn Ancient Power once it reaches level 28, Moltres learns it at level 29 and Dunsparce at level 41.
Take the Pokemon to the Move Tutor house in the Frontier Front area. The Move Tutor on the upper right of the home will teach Ancient Power for 40 Battle Points.
Breed a pair of compatible Pokemon to create a new creature that knows Ancient Power upon hatching. Several specific egg groups determine which Pokemon can interbreed. If the male knows Ancient Power, and the baby has the potential to use it, the baby will be born with the attack. For instance, if a male Kabuto mates with a female Crawdaunt, the Corphish they produce will be born with Ancient Power.