Installation is the same as any python package, e.g.:

wget --no-check-certificate https://bitbucket.org/pyspeckit/pyspeckit.bitbucket.org/get/tip.tar.gz
tar -xzf pyspeckit-pyspeckit.bitbucket.org-tip.tar.gz 
cd pyspeckit-pyspeckit.bitbucket.org-tip
python setup.py install

or if you have pip:
pip install https://bitbucket.org/pyspeckit/pyspeckit.bitbucket.org/get/tip.tar.gz
