apt-get update

# Remove libx11-6 to remove x11 and all dependent packages (anything GUI related, basically)
apt-get remove libx11-6 libgtk-3-common xkb-data lxde-icon-theme raspberrypi-artwork penguinspuzzle

# Clean up redundant packages
apt-get autoremove

# Purge config files for removed packages
dpkg -l | awk '/^rc/ {print $2}' | xargs dpkg --purge