You can download the client by typing the following command:

svn co svn://svn.savannah.nongnu.org/h-client/trunk/h-client

In order to install it type:

python setup.py install --user

and run it using:

~/.local/bin/h-client

(or just h-client if added ~/.local/bin to PATH).

If you are using Trisquel 4.0 you have to comment the row starting with "pycurl" inside the file setup.py (see the below piece of code) and install pycurl by means of the package manager

     install_requires=(
#        "pygtk",  # tries to get an old version
        #"pycurl"
        ),
    )

You have to install Distribute, pyGTK and pycurl before (they would most likely be already installed). Python 2.6 or 2.7 is required.