To uninstall debian-edu-artwork just follow these instructions.
/debian/stretch/main///install/index.html Debian Edu themes and artwork Debian 9.0 graphics 0.902-3
sudo apt-get remove debian-edu-artwork
Which will remove just the debian-edu-artwork package itself.
sudo apt-get remove --auto-remove debian-edu-artwork
This will remove the debian-edu-artwork package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for debian-edu-artwork then this will work.
sudo apt-get purge debian-edu-artwork
Or similarly, like this debian-edu-artwork
sudo apt-get purge --auto-remove debian-edu-artwork
|Maintainer||Debian Edu Developers
|Description||Debian Edu themes and artwork|