Pull the Bosch dryer away from the wall and unplug it. Never attempt any replacements or repairs without first disconnecting the dryer from the electrical outlet. Also turn off the gas running to the dryer.
Remove the screws that secure the small access panel on the front of the Bosch dryer. The exact location of this panel varies from model to model, but it is generally quite easy to spot. Shut off the gas valve after opening the access panel.
Remove the nut that connects the burner system to the gas valve, then remove the screws that connect the burner system to the dryer. These screws should be on the side opposite the gas valve.
Unscrew the screw from the bottom of the burner system and carefully lift it out of the Bosch dryer. Disconnect the wires leading from the igniter to the burner system. Loosen the screw that holds the igniter cover to the igniter itself.