site need de-indexing?

Guys please can you help me out,what can someone do to get a particular post on your blog de-indexed by google?

it's pretty much easy set your meta tag to noindex, then request deindexation from Google Search Console, open it, click on the switch to an old version then click on Google Index and Remove URLs then simply enter URL.
That will do a job. Just give it a time it may take a few weeks.

yes i know that lets say someone who has no access to do that,what do you till such a person would have done to your website