Só seguir estes passos:
No terminal:
sudo apt-get remove avant-window-navigator avant-window-navigator-data awn-settings awn-applets-c-core libawn1 vala-awn && sudo apt-get autoremove
Uma linha de cada vez:
sudo add-apt-repository ppa:awn-testing/ppa
sudo apt-get update
sudo apt-get install avant-window-navigator-trunk avant-window-navigator-data-trunk python-awn-trunk awn-settings-trunk awn-applets-python-core-trunk python-awn-extras-trunk awn-applets-python-extras-trunk awn-applets-c-core-trunk awn-applets-c-extras-trunk
Para instalar o dockmanager:
sudo apt-get install dockmanager-daemon dockmanager