Changing light inside heater unit

Does anyone know how hard it is to do or what the procedure is for replacing a burnt out light behind the heater inside the dash?


Thanks,

Brad

PS. My "check engine" light has came on 2 days after I installed the PIAA lights....any correlation here? The car is running fine, gas cap on tight and it's been over a week now and its not shut off. May have to do that trick that the other member recommended.