Instructions
Select the Polar Base map in deathmatch.
Open the door in the room you start in using the "Hacking" option.
Run out and turn left toward the wire fence. Climb up the fence and drop down the other side.
Locate the pylon on the corner and the cable hanging from it. Jump up onto the cable and shimmy across the gap.
Drop down onto the building on the other side by hanging upside down and then releasing your grip. You should land with the roof coming up to your character's knees.
Run across the roof toward the street light and jump onto the light. Jump from the street light over the fence and outside of the Polar Base.