How do I remove evaporator cover

[The Colonel]

We just started getting a musty odor when AC kicks on. The two return filters are clean. The coils on both components were dirty. I went on top and cleaned the condenser coils with coil cleaner and water and sprayed cleaner through the two vent holes onto evaporator coils twice, but still have odor. I’m not sure how to remove the cover up top to get to it better and check the drain. The cover is covered in styrofoam and appears to be solidly attached. There are several plastic latches around it but also some screws. Can anyone tell me how to get cover off? Thanks
It’s a dometic 15k I believe