Whirlpool Dryer Not Heating

How do you remove the heater box? I need to check the dryer heating element. I recently ordered part # AP3094224, thermal cut-off kit and the top thermostat has now stop working after a few days. Can I order just the top thermostat? Is it part #2924?

How do you determine if the adjustable dryer cycling thermostat needs to be replaced?

My dryer also trips the main house breaker (200 amp.) when the heating element stops working…