How to find a new PhD advisor if relationship with current advisor is not working out?
If you feel you must change your adviser, it is essential that you speak to the adviser before discussing the possible change within anyone else in your department.  It is best to be as honest as possible, since usually advisers are experienced in working with students, and do not appreciate an explanation that might appear ingenuous.  Also, your request could reflect poorly on your adviser if you speak to someone else in your concentration.  I would sit down and carefully make a plan of action to use in bringing up the subject. In addition, try to learn as much about your adviser as a person. For example, is he or she vindictive, intolerant, considerate, etc.  That will help you frame the way you approach the subject.