If you have discovered pages that you want to remove from Google’s index, there is a simple two-step process you can use.
Simply removing the page from your website does not remove the age from the index. In fact, this can exacerbate the situation.
Step 1: Add the NOINDEX meta tag to each page that you want to remove from the index. Put this tag in the header, alongside your other meta tags. If Google crawls your site frequently, they may notice the change, but it may take weeks before they remove it from all of their servers.
If you need to remove the page right away, proceed to step 2.
Log in to your Google Webmaster Tools account in Step 2.
Select the “remove a page from the index” link from the Crawl menu. Simply enter the URL of the page you want to delete. They will look for the NOINDEX meta tag, so don’t do this until you’ve finished step 1. This manual process should reduce the time to days rather than weeks.
Taking the page off your website will not solve the problem. This page will still be indexed by Google, and if someone finds it in a search and attempts to click on it, they will receive a “404 – page not found” error. Not only is this poor usability, but Google will not rank sites with a high number of 404 errors.
The use of robots.txt
You can also tell Google not to crawl or index your site’s pages by using your robots.txt file to tell the search engine what to crawl and what not to crawl. This is especially useful if you need to manage entire directories of pages.