But what if your website is already indexed? How do you remove them from the list? This, however, might depend on the case, which is explained by Google here. But Google might take its sweet time in crawling through the page, so it won’t get done quickly, so you have an alternative.
If the site in question is verified with your ownership, you will find an option called URL Removals under the diagnostic tab in your webmaster tools account. By choosing “New Removal Request” you can pick out a particular website to be removed from the index.
But the removal can be done through individual URLs, caches, content, and everything else in the website. For more details as to their individual requisites and process, go