A malfunction warning came on saying the left "stop light" was out. How do I change it and which bulb is it?
I bought this car new and take it to the dealer for service and whenever there is a problem. But every time I take my car to the dealer, it takes such as long time that I was just hoping to avoid that.

all the mercedes ive owned were the same. open the trunk,
look on the side you want to change, some you pull the bulb out, some others has several nylon twist bolts which you have take the intire bulb holder out where all your tail light bulbs are and remove and replace the bulb thats burned out...

Take it to the dealer.

Read the manual that's how i changed my light on my Mercedes