Installing and removing specific version of Docker

Add repository to your apt source :http://docs.docker.io/en/latest/installation/ubuntulinux/#ubuntu-raring

One you're done. Uninstall previous version if any
$ sudo apt-get purge lxc-docker
Now you may install other specific version

$ sudo apt-get install lxc-docker-0.6.6

Now, you can confirm it by getting docker version
$ docker -v