The control is connected by two wires. Label the wire placement on the control before disconnecting the wires. The wires are connected to the switch with slip-on connectors. Firmly pull the connector (do not pull on the wire) off of the control's terminal. You may need to use a pair of needle-nose pliers to remove the connectors. Inspect the connectors for corrosion. If the connectors are corroded they should be replaced.
To test the temperature control before replacing it, click here for instructions.
The temperature control also has a temperature probe permanently attached. Follow the path of the probe and remove any fasteners that hold it in place.
Carefully replace the temperature probe along the same path as it was originally installed. Avoid any unnecessary bending, and do not bend it into a sharp angle as this can damage the probe. Connect the wires to the new temperature control. Replace the switch and housing (if any) and press the knob onto the the control's hub. Adjust the control to a midway setting. Plug in the freezer. After one to two hours check the temperature.
If there is also a freezer control, it can be replaced in the same way.