To remove indexed files or folder from Search Engines edit robots.txt file in the webroot.
Editing of robots.txt will affects the next crawling of search engines.
This editing is directly related to SEO. So be careful to edit this file.
This robots.txt tells the search engine to which files should list/not.
So you don’t want to show the file or folder in search engines add it in robots.txt with Disallow command like below.
disallow command will instruct the search engine to don’t crawl the file/folder. Here, the wp-admin folder is excluded from the search engine listing.
So use it carefully, something wrongly put will negatively affect your website ranking.