I have an application running as a service on an Ubuntu Linux machine that I no longer need so want to stop it and remove is as a service to make sure it doesn't get started automatically on system start up.
I'll test this out using the service I previously created in Add a Linux Service on Ubuntu. First the service needs to be stopped, the systemd script deleted, and the service registration removed.
$ sudo service hello stop
$ sudo rm /lib/systemd/system/hello.service
$ sudo systemctl daemon-reload
$ sudo systemctl reset-failed
Now check that the service no longer exists.
$ service hello status Unit hello.service could not be found.