The amber light under my entry step is not working. I tried to remove the lens from the fixture to check the bulb but it didn't unscrew or pop off easily. What's the correct method for removing the lens? The owner's manual references a circuit breaker in the front electrical bay (CB9). How do I determine which breaker is 9? Once I locate it, how do I test it? And is there something other than the bulb and circuit breaker I should check? Thanks!