Epic Crossfire Glitch

This is inside the huge tank thingy on the map (port? IDK, thats what I think)

If you get under the map and walk along the edges of the outside there should be thin stairs, invisible stairs, from there you get up outside the map and you must climb up to the roofs, then you can jump into the tanker with a speedhack.

You can shoot out and can't get shot.

PIC:

you should post a vid or somthing on exatly how to do it