The temprature of my refrigerator has been warming up gradually, so I had a repairman come and check it out. He tells me that the control board/motherboard needs to be replaced, and that a new sensor kit needs to be installed as well, quoting a cost of about $300. I think I’m pretty handy 
, so I’d like to save some $$ and do it myself. Is this something I should leave to the pro’s, or is it pretty safe to buy the parts and do it on my own?