Turn off the power supply for the dishwasher at the main circuit breaker. Either flip the switch to the "off" position in the breaker or remove the fuse as necessary to cut the power.
Open the dishwasher door.
Remove any knobs from the front of the dishwasher control panel by gently prying them off with a screwdriver.
Look for the screws holding the control panel in place on the front of the dishwasher. These may be on the sides or they may be covered with plastic tabs that need to be pried off first.
Loosen the control panel screws. Pull off the control panel.
Remove the dishwasher door vent from either underneath the control panel or the slot where it is mounted in the door. Insert a flat-bladed screwdriver or a putty knife behind the vent and gently pry it forward to remove.