You should either go to a certified Mercedes Mechanic or a company such as AutoZone. You can get a new headlight there, and they include instructions.
how to replace the headlight
how to replace the headlight light assemble on a 2001 e320
Remove the wiring harness from the back of your 2007 Mercedes-Benz headlight. Remove the headlight retaining bolts. The headlight will come out. Reverse the process to install your new headlight.
pop out the bulb. replace. Please be a little more specific.
how to replace 2007 Mercedes GL450 Headlight Bulb Low Beam
How do you change the headlight on a 240D mercedes?
take the big thing of and twist the bulb and put it in
Either from a Mercedes dealer, who can order one for you . Or from a breaker's yard, dealing in European cars.
Carry it to dealer who will replace on low beam headlight for $15 +/- dollars in about 5 minutes.
how to change headlight on 1999 Mercedes e350
call car talk look it up on google.
On older vehicles you replace the entire headlight. On the newer vehicles you just replace the bulb unless the headlight assembly is damaged.