Take off plastic back panel in centre of machine at rear attached by two screws. Then remove the raised panel which is attached by approx 8- 10 screws. inside this panel is the thermostat which is then removed by two screws on the raised panel. Once removed, you will see three small disks. one of the disks has a hole in the centre. press the hole with a pin and you will here it click. put back together, and your thermostat has been reset.
Make sure you have cleaned all vents, as this may have been the cause for the thermostat tripping in the first place.
Dean, October 2010