Sahih Muslim Book 025, Hadith Number 5332.

Chapter : Excellence of changing ugly names to good names.

Ibn 'Umar reported that Allah's Messenger (may peace be upon him) changed the name of 'Asiya (Disobedient) and said: You are Jamila (i.e. good and handsome). Ahmad (one of the narrators) narrated it with a slight variation of wording.