How can a werewolf who was a human become human again?

Speaking just pertaining to mythology, because werewolves don't exist, many mythologies have cures for the werewolf. Greco-roman sources say the werewolf could cure themselves through exhaustion so they would fore the victim through great physical labor. Medieval Europe had cures which included wolfsbane, exorcisms and surgery. Where Christian belief was strong they believed that a werewolf could be cured by repeating its Christian named thrice or a devotion to St. Hubert (patron of dogs).