To uninstall manpages-fr-extra just follow these instructions.
/ubuntu/trusty/universe///install/index.html French version of the manual pages Ubuntu 14.04 LTS universe/doc 20140201
sudo apt-get remove manpages-fr-extra
Which will remove just the manpages-fr-extra package itself.
sudo apt-get remove --auto-remove manpages-fr-extra
This will remove the manpages-fr-extra package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for manpages-fr-extra then this will work.
sudo apt-get purge manpages-fr-extra
Or similarly, like this manpages-fr-extra
sudo apt-get purge --auto-remove manpages-fr-extra
|Description||French version of the manual pages|