Our strat: Haul ass straight into the room (or through the left hallway but good luck getting through the mob) and as you see the stairs on your left jump catty corner (left) over the stairs and railing onto the boxes there. Immediately jump up onto the balcony and pull out your ghost to open the door. Once inside have one person stand at the back (the door behind this door) to prevent vandal spawns, then have one person stand close to the main door you used the ghost on and hold his ghost open so the door doesn't close. 3rd person shoots, rotate positions to allow heavy timer to expire.