You have to have a shield. Plant the shield on the steps next to the railing, next to the spawn point.

Have someone stand in front of it by at least one foot, the other person needs to be far enough to roadie run.

When you get close to the person in front of the shield, while running, press A to take cover on that person.

When you are taking cover on that person do a mantle over that person like you would a wall and if you did it right you should be under Blood Drive and you can see through the stairs.