1998 Dodge Caravan Changing Air Filter

I own a caravan 1998 and i do not know how to get the air filter cover off the canister. there are two nuts securing it to the front framework. I loosened these and removed them but the top half of the canister does not come off easily. Do i pry the cover of the air filter housing with a screwdriver or is there some trick that will make the job easier that I am not aware of. any help is appreciated.