fridge & freezer stopped keeping things cold

I turned off and emptied my fridge/freezer, unpluggedit, and removed the two tiny bolts holding the back plate on the inside of the freezer. The coils were thick with ice, so I put a small heater on a shelf in the freezer for 10 minutes. This helped all the ice to melt and drain onto towels I had put on the bottom of the freezer.
I then unscrewed the two screws holding the part in place, disconnected the wires, installed the new part, and put all the screws back in. Presto it was done. This was easy even for a "girl" like me.
Note: the repair itself took only 5 minutes, but I took my time thawing the coils to avoid any mess.