1) Make a male Rampardos, Blastiodon, Tyrantum, Aurorus, or any pre-evolution of the four learn Ancientpower. Levels learned here.
2) Breed a your Ancientpower Pokemon with a female Charizard.
You just hatched an Ancientpower Charizard. I would actually suggest Steel Wing over Metal Claw though, because Steel Wing is more powerful with only 5% less accuracy.
Steel Wing is learned through TM51.