Turn off the air conditioner by dialing the control knob to the "Off" position or pressing the "Off" button on the front panel of some electronic models.
Press down gently on the top lip of the grill with one hand while pushing up with your other hand against the bottom lip of the grill. Flex the plastic grill slightly to disengage from the notches on the front of the unit.
Tilt the top of the grill toward you and lift to remove the grill from the air conditioner. The filter behind the grill snaps out with gentle pressure on the left and right sides.