You can uninstall or removes an installed gstreamer0.10-plugins-ugly package itself from Ubuntu 14.04 LTS (Trusty Tahr) through the terminal,
$ sudo apt-get remove gstreamer0.10-plugins-ugly
If you would like to remove gstreamer0.10-plugins-ugly and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove gstreamer0.10-plugins-ugly
If you use with purge options to gstreamer0.10-plugins-ugly package all the configuration and dependent packages will be removed.
$ sudo apt-get purge gstreamer0.10-plugins-ugly
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove gstreamer0.10-plugins-ugly