This can be obtained at the end of the first level, Schöneberg streets.
Simply follow the waypoint markers to the top of the building, wait for the cut scene and then shoot the satchel charge you placed earlier earning you:
After the convoy has been stopped and you have shot several of the troops a tank will arrive. You need to shoot the red cap on either of the fuel tanks at the back. My first shot was miles off so I tapped RB to enter without focus mode, I still missed a few times but I got there in the end.