You can uninstall or removes an installed libreoffice-style-galaxy package itself from Ubuntu 14.04 LTS (Trusty Tahr) through the terminal,
$ sudo apt-get remove libreoffice-style-galaxy
If you would like to remove libreoffice-style-galaxy and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libreoffice-style-galaxy
If you use with purge options to libreoffice-style-galaxy package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libreoffice-style-galaxy
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 libreoffice-style-galaxy