Unplug the dryer from the wall.
Remove the lint screen from the dryer. Remove the two screws from the opening. Pry a putty knife between the top panel and the main body of the dryer and lift up on the top panel to expose the inside of the unit.
Pull on the door switch wire connector to unplug it. Remove the screws from the front panel and pull it off.
Push down on the idler pulley to release the drive belt from the motor shaft. Use the dryer belt to lift up the tub. Locate the ignitor on the burner tube.
Pull on the wire connectors attaching the ignitor. Inspect the filament end for burn marks or cracking. Set a multimeter to the lowest ohm resistance setting. Touch one probe to each terminal inside the burner wire. If you get a reading between 40 and 400 the ignitor is good. If not, the ignitor needs to be replaced.
Plug in the new ignitor and reassemble the unit by reversing the take apart instructions.