Ha !!! I just figured out this very problem...
When you open the hood, right above the turn signal is an access hole. You have to insert a screwdriver (use the flat blade of the one in your trunk tool kit if you have it) into the access hole and push down on a clip at the extreme back of the light assembly. It's not apparent until you get the thing out, but the clip is a different color than the housing. Mine was grey and the mail headlamp housing is black.
You should hear a small click when it disengages... when that happens, simply pull the assembly forward and replace the bulb.
Mine seemed impossible at first, but painfully simple once I found the clip to push on.
Good luck!!