Me and 5 friends tried this last night and everyone agrees that the stairs part is ridiculously hard but we all managed to get it eventually. Everything else is pretty simple. We also did something pretty sick.. If you guys manage to get out of the map keep going straight until you can see a house in the distance and find the barrier where you can fall to your death and have someone lay prone there.. Now run and jump onto him and propel yourself all the way to the top of the house. From there you can pretty much run as far as you want.