Could you please tell me how to replace the defrost control board (part #2304099) and the thermister (part #627985)? A diagram of where these parts are located would be helpful. Also, is it common to have the refrigerator click when these parts are bad? I understand that the clicking can come from the relay, or is the relay just making this noise due to the frig not defrosting? Unplugging seems to reset the relay, so no clicking noises are heard. Is it necessary to replace the relay in addition to the other two parts?