I'm removing the Uber "tip" as it seems most people aren't having any luck with it. I did all of these on I Am Death Incarnate difficulty and you probably should too.
This is a video of the Graveyard Challenge Map in Wolfenstein: The Old Blood.
To obtain Gold, you must be playing on "I Am Death Incarnate" or "Uber" difficulty. The gold medal is rewarded at 28800. For higher scores go for headshots (600 points) and try to keep your combo active as you receive an extra 200 points for each kill in the combo.
To reach Gold, you must enter the side area located to the right of where you begin. I saved this area until after I killed the main group of enemies.From Ernap:
You can enter the 2nd Area from the Exit instead of the Regular Entrance by jumping like crazy at the Hole. This will give you a major Advantage as no Enemy can get to you and you can easily line up your shots