If you install PyFFI manually, and you already have an older version of PyFFI installed, then you must uninstall (see Uninstall) the old version before installing the new one.
If you have setuptools installed, simply run:
easy_install -U PyFFI
at the command prompt.
You can uninstall PyFFI manually simply by deleting the pyffi folder from your Python’s site-packages folder, which is typically at: