OK...You said 'topdoor' and refered to other five. I see five levels total. Is the top a flip up door with compartment inside? and others, doors or drawers? It will have an interlock that should only allow one drawer to open at a time. If you can get into the side through whatever opens, you should be abel to lift the lock latch bar. If its a door on top, it may need to be fully opened to unlatch the lower drawers.