a class side light bulb replacement

you have to unbolt the wing scott,
undo the wings top bolts, and pull back gently,(it's plastic)
then undo the nuts holding in the light,
don't get mad if the light won't come out first time (took me ages)
you have to remove the complete light to replace the lamp
unless you have very small hands!
another royal a class pain in the ass!

 

if i'm not mistaken, are you refering to the indicator light which would be located in the side mirror of that vehicle?

If you mean the the bulb in the headlight, not sure about a '99 model, but on my earlier model i have the jack up the vehicle with the steering turned to give maximum access. then you will find a access panel you have to open up to allow access to the back of the lights. A complete pain in the a$$ but its the only way to get it done.