1) One who wants to repeal a vow or an oath, must go to three learned men, of whom at least one must be an expert in the laws of vows, (so that he will know which vow can be repealed and which one cannot, as well as how to repeal it), and they will repeal it for him. (Kitzur Shulchan Aruch 67).
2) If one makes a vow in a dream, it is good to arrange for ten learned men to repeal his vow. (ibid).