$ sudo apt-get remove libreoffice 

Uninstall libreoffice including dependent package

If you would like to remove libreoffice and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libreoffice 

Use Purging libreoffice

If you use with purge options to libreoffice package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libreoffice 

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 

See Also,