NMO loading

[ncsxn]

Hello,
not a person with a deep understanding of this area...
Can someone please explain to me more elaborately how to run NMO custom levels?
I don't understand this step: "You can load a standard original Ballance NMO level by clicking start > NMO level."
There is no such option in the game.
I am using the 1.0.7 version - what to put where? Do I need BML?
When I use BML, there even is some test NMO level that doesn't appear anywhere when the game is launched.
Is Win 64-bit such a problem that it would not even show those levels?
Thanks in advance.