[SOLVED] How do I stop the Ui from running on startup?

Hidy ho all,

I'm working on keeping some older skills I have, sharp. And one of those skills is, or was, setting up an apache server, to run a website. Now I did this 9 or 10 years ago, and last I heard, that server was still hosting the website. Though I have fallen out of touch with that place, so it could have been replaced by now.

Now, I managed to setup a new apache server, recently. But while I was asking questions on that topic, it was pointed out to me that most web servers only run their cli, to save resources for the actual website hosting. So, I decided to try and stop the ui from running on a vm of Ubuntu 15.10 (32 bit). And disable its ui completely, so I only have the cli to work with. Then setup the server again, that way.

Only trouble is, the Ui doesn't seem to want to be disabled. I followed these instructions, but the ui is still appearing at startup. Is there a way to simply stop the user interface from running at startup? Or do I have to remove it completely? If its the latter, then how do I go about removing the user interface from an Ubuntu desktop?