The freezer did not defrost anymore and considering the age of the fridge (18 years) I tried to order a replacement. Due to covid, the one I wanted was not available and others had months of delivery time. So I figured out by Googling that when I left the freezer door open overnight by accident that the defrost thermostat must have given out. On the inside of the freezer I opened up the back (about 8 1/4" nut screws)I compared the replacement part picture on this website to the one in my fridge (which was visibly broken) and ordered it. Came within 2 days, as promised. I completely defrosted the freezer with the help of a small fan, unplugged the old one and plugged in the new one, put the cover back on, and screwed it in (one screw did not take anymore but the backplate stayed nicely in place anyway). Defrosting and cleaning took most of the time. Figuring out what was wrong was the most difficult.