Replacing dishwasher air inlet

How do you replace the air inlet located at the bottom of the dishwasher door. I have removed all of screws apparentely holding the door and stainless steel door panel together but I still cannot easily separate them. The plastic air inlet is held in place by two screws but to access the screws I need to separate the exterior and interior door sections. I really would appreciate any help. I feel this should be an easy thing to do but I have not been able to get it done.