This achievement relates to a woman named Galathil, who resides in the Ragged Flagon under Riften. She will allow you to alter your features for the meagre price of 1000 gold; this includes pretty much all of the character alterations available to you at Helgen (when you first started the game).
Keep in mind, though, if you become a Vampire Lord before going to see her, she will refuse you. Her techniques only work on the living, not those who have crossed over into undeath. If you've turned yourself into a Vampire Lord, do the Companion's questline and turn yourself into a Werewolf. If you've already done the Companion's questline, talk to Aela the Huntress, and she will turn you.
Also, if you're turned to Vampirism against your will (infected in a fight with vamps, basically) there is a quest called Rising At Dawn, wherein Falion of Morthal will turn you back into a human for a filled Black Soul Gem. If you're in the Dawnguard, you can get this quest from Isran at Fort Dawnguard. If you're with the Vampires, you hear it in passing at the Vamp HQ, Castle Volikhar.