We have a Heartland 30RKS North Country. We have a small light between the dinette and the sofa. Fixed to wall. Small lampshade. Unscrew top, take lampshade off. Two cylinders appear, about 4" high. Bulbs in tops. They have blown. How do we remove bulbs ? Have tried pushing down and twisting - no good. Have tried just twisting - no good. Advice please ! Thanks.