Hero save glitch on the Find the Archaeologist Quest. Bypass the stones and go to the Temple of Avo and donate 48,000 to 54,000 gold to get youth. Hero save, reload and do it again until you reach the age you want. 18 is the lowest you can go.
Don't have the gold to repeat this, donate the amount specified and rapidly press the (A) button until the donate screen comes back up again and you keep your money, but the donation stills counts. To make it take affect to get what you want, donate 1 gold coin afterwards.