$ sudo apt-get --yes autoremove --purge flashplugin-installer
$ sudo apt-get --yes autoremove
$ sudo sed -i "s|\(# deb http://archive.canonical.com/ubuntu \)\(.*\)\( partner\)|deb http://archive.canonical.com/ubuntu \2 partner|g" /etc/apt/sources.list
$ sudo apt-get update
$ sudo apt-get --yes install adobe-flashplugin adobe-flash-properties-gtk