most of the themes must be fine tuned with "appearance" or "customise" menu

I found out how t do it, problem solved.

Well guys I stumbled upon how to do it. In the managing your sites my sites had a red X next to them that did not show up in some browsers. I just clicked on it and, walah! site is gone. I like when things fall into place. :)

Is the site on your own domain, or are you asking about a siterubix site?

I suggest not deleting it if you bought and own the domain name, e.g.
yoursite dot com, in which case you can use the site as a test site for trying out plugins and themes.

~Jude

here you go - look for the red button next to 'site health.'

Are you sure you want to delete it though?