Product review (1 stars): Update:  Easy Fix but a bad deal overall
Be sure to follow the instruction videos on doing this repair, especially making sure to disconnect the dryer power cord from the outlet.

Depending on your model, this could be a 15-30 minute repair.  It is always best to replace both thermostats at the same time.  The instructions say that if one or the other of the thermostats do not show continuity, then you should replace both.  However if either of the thermostats show continuity but have a measurable amount of resistance (above 5 ohms), then the thermostat may be shutting off heat prematurely and should also be replaced.

Edit:  Not 10 months later, the thermostat failed completely. I can't recommend a part that dies after such a short amount of time.