you have to find the bazooka team which is by the way dead. once you eliminate all the snipers then retrace your steps and go through all the houses. in one of the buildings you'll find the bodies of the bazooka team. you must pick up the bazooka to mark it down as complete. then you can just wait by the gates for waffen ss soldiers to come patrolling through or you can blast the gate open with the bazooka