I am fitting a new thermostat to a Diplomat 3300 oven and am struggling to get the old one off. I have removed the control knob on front of the oven and located the old thermostat inside the oven. I have taken the wires off the old one and fixed to the new one, but I can't work out how the old one is fixed to the inside of the oven. Can you help

Jeannette Astin, February 2011