Then pull off the two large plugs, one on each side of the control unit. Don't pull or pry too hard or you risk pulling the cover off the back of the plugs instead, potentially sending wires everywhere! Just take your time and wiggle them off gently.

You can now remove the control unit and perform any work on it you need to (re-soldering of cold joints, for example) or you can install a refurbished unit like the Programa unit pictured.