systemctl
systemctl list-units --type=service
OR
systemctl --type=service
systemctl list-units --type=service --state=active
OR
systemctl --type=service --state=active
# systemctl list-units --type=service --state=running
OR
# systemctl --type=service --state=running
systemctl stop [servicename]
systemctl disable [servicename]
rm /etc/systemd/system/[servicename]
rm /etc/systemd/system/[servicename] # and symlinks that might be related
rm /usr/lib/systemd/system/[servicename]
rm /usr/lib/systemd/system/[servicename] # and symlinks that might be related
systemctl daemon-reload
systemctl reset-failed
# It is possible that the systemd service 'wraps' the old style scripts in /etc/init.d, so you may want to clean that up too, but that is not where systemd services live.