how to remove software on ubuntu

    The last day-to-day package operation is removing things you no longer want. This is done through the apt-get remove command, as follows:
howard@howard-OptiPlex-320:~$sudo apt-get remove firefox
    Removing packages can be dangerous, because APT also removes any software that relies on the packages you selected. For example, if you were to run apt-get remove libgtk2.0-0 (the main graphical toolkit for Ubuntu), you would probably find that APT insists on removing more than a hundred other things. The moral of the story is this:
    When you remove software, read the APT report carefully before pressing Y to continue with the uninstall.
    A straight apt-get remove leaves behind the configuration files of your program so that if you ever reinstall it, you do not also need to reconfigure it. If you want the configuration files  removed as well as the program files, run this command instead:
howard@howard-OptiPlex-320:~$ sudo apt-get remove --purge firefox
    That performs a full uninstall.