You need to use 'easy_install' script from your $PYTHON_PATH/bin folder. Like:
easy_install python-msp430-tools
It will download package from pypi and install it. You dont have to download it by hand. You also can use pip
in the same way after installing it. So once:
easy_install pip
Then:
pip install python-msp430-tools
Pip is much better in package management.