Light out on cabin temperature control knob
 

Hi guys -- these threads have been enormously helpful in fixing issues with my 2009 Honda Fit (Base).
The cabin temperature control knob (round, has a semi circle of blue to red dashes along the circumference) doesn't light up anymore. My wife and I were debating whether it lit up in the past, and as far as we can tell it did. We only noticed after the rear defrost button stopped lighting up too (and, I found the fix for this on here!)
Anyway, any idea what part(s) need to be replaced to fix this and also where I can find the replacement part?
Then once I find that how I can get the old knob off and replace the broken bulb/parts?

thanks!