You'll then be ordered to repel the counter attack, and eliminate the 3 remaining German officers. He takes a long time to fire, so lining up the shot shouldn't be hard. When you find them you'll have to take out the sniper in the building across the court yard. When you get there you will be told of a missing sniper team. After destroying the rest of the AA guns you'll be told to assemble at the North gate. Meaning when facing away from the Town Hall go left or right, your choice.
Then head to the Hill Houses or North East.
Get to the roof and destroy both AA guns. There is an MG nest at the top of the Stairs, but you can avoid being out in the open by going in the door to the right of the main door. You'll end up having to clear it twice, but trust me, it's better this way. I suggest clearing the tower (skill drop one) and clearing the town hall first. Your first 3 objectives you'll be taking out AA guns Town hall, hill houses and a North East gun. Eliminate the 3 German Officers at the Town Hall.