I don't understand how to install this .3dm importer (Rhino to blender 2.82)

Hi, I’m trying to import a rhino 6 file into blender while keeping the layers.

i’ve downloaded “Rhnio3DM” from github and installed python 3.7, but i don’t know how to install a dependency. (i’m a complete noob at this). I’ve also tried this “import_3dm-master.zip” from github too, but the file is like 260kb, so i thought it was an addon, and i tried installing it as one in blender, but it’s not showing up on the list to be activated…

could somebody walk a novice please…?