git clone https://github.com/davepeake/oscar2nrrd.git
git submodule init 
cd pynrrd
python setup.py install

usage: oscar2nrrd.py [-h] [-v] [-o OUTPUT] [-s SPACING] filename

positional arguments:
    filename              Filename to convert

optional arguments:
    -h, --help            show this help message and exit
    -v, --verbose
    -o OUTPUT, --output OUTPUT
                        Output filename (Defaults to the input filename with
                        an nrrd extension)
    -s SPACING, --spacing SPACING
                        Spacings