If they are like mine, the covers are just pressed on but they are a tight fit. I used a paint can opener (the little curved end ones that are free at Home Depot) to pry of the grill away from the ceiling. I used a putty knife as a backing on the ceiling and a small block of wood as a lever also.
2013 26BH ghetto model w/ 4 plain rims and some rust
2001 Silverado 2500HD 6.0 gasser
I have a fever...and the only cure is more camping!