Check the fuse when the current flow through the power cord, but not through the heater coil.
Flip the device over so the bottom is facing up.
Remove the two 10mm screws holding the back panel using a Phillips #2 screwdriver.
Place the Flathead Screw driver parallel with the gap between the back and the heater body, then twist until the two parts of panel are separated. You may have to do this on four sides of the panel.
Remove the front panel by pulling them apart. The front panel should come out easily.
Remove the two dial caps from the two switches by lifting them up.
Pry one end of the fuse from the bracket until it is separated from the holder.
Remove the fuse by lifting it up.