The Vivi's are some of the easiest one's to re-coil . If you can't do these , don't bother buying any re-buildables . A waste of your money . As said earlier , lots of video'a on Youtube . I watch one , and took all of 5 minutes or less to do one myself . Came out to 1.9 ohms , which is real close to one of the one's , that comes with it . Cost , maybe 10cents .