What tool can I use to manage upstart services?

How should I configure upstart runlevels ? Of course I could edit /etc/init/XX but that wasn't right way to do this, I think.

yup! you have a tool , of course GUI .

Open your terminal and type this

sudo apt-get install bum 

Type as BootUP Manager in unity dash , that will open .

Technically the .conf files in /etc/init/ are configuration files so you are free to edit them.

In Ubuntu 11.04 and later you can use .override files to modify Upstart jobs without modifying the .conf file: To modify the job foo as defined in /etc/init/foo.conf create /etc/init/foo.override and put kin the things you want to change.

Unfortunately the documentation for the .override files seems to be a bit poor so I'm not really sure about the details here.

Upstart Intro, Cookbook and Best Practises uses an override file containing a manual stanza to prevent an job from beeing started automatically:

echo "manual" >> /etc/init/myjob.override

Just copying the .conf file into the .override file seems to work, too.