The easiest way to install additional python packages is to use pip (which will download the package directly from pypi.python.org). Before using pip in Sim4Life 3.x, there is a small conflict between pip and setuptools that first needs to be resolved. Here is how you can do it:

  1. Open a console (using for example "cmd.exe"). Note that it does NOT have to be run as administrator.

  2. Type the following commands in the console

cd C:\Program Files\Sim4Life_v3.2.4.1836\Python27
python.exe -m pip uninstall distribute (and type "y" when prompted)
python.exe -m pip install --upgrade setuptools
python.exe -m pip install name_of_new_package_to_install

EDIT: in Sim4Life 4.x and above, there is no conflict anymore between pip and setuptools, so all you have to do is:

cd C:\Program Files\Sim4Life_v4.0.0.2835\Python27
python.exe -m pip install name_of_new_package_to_install