Sadly (and curiously) enough I don't see any hints on it in this forum
Unzip the mod (if it's archived). A regular mod would contain some of such folders:
These (if they're present) must contain some folder resemling mod's name, such that it doesn't intersect with existing contents of original Notrium's folders (data, music, sound, textures). So you can just copy these folders into Notrium's folder. That's all. Enjoy.