google webmaster central blog shared tips to remove contents if google's still showing old, removed content in search results, either in the form of a "snippet" or on the cached page that's linked to from the search result. As an example, let's look at the following fictitious search result:
To change the content shown in the snippet (or on the linked cached page), you'll first need to change the content on the actual (live) page. Unless a page's publicly visible content is changed, Google's automatic processes will continue to show parts of the original content in google search results.
Once the page's content has been changed, there're several options available to make those changes visible in search results," informs google:
- Wait for Googlebot to re-crawl and re-index the page
Once we've re-crawled and re-indexed the page, old content will usually not be visible as it'll be replaced by the current content. Provided Googlebot isn't blocked from crawling the page in question (either by robots.txt or by not being able to access the server properly), you don't have to do anything special for this to take place.
- Use Google's public URL removal tool to request removal of content that has been removed from someone else's webpage. Using this tool, it's necessary to enter the exact URL of the page that has been modified, select the "Content has been removed from the page" option, and then specify one or more words that've been completely removed from that page.
Once your request has been processed and it's found that the submitted word(s) no longer appear on the page, the search result will no longer show a snippet, nor will the cached page be available.
Keep in mind that we'll need to verify removal of the word(s) by viewing the page. If the page no longer exists and the server is returning a proper 404 or 410 HTTP result code, making us unable to view the page, you may be better off requesting removal of the page altogether.
- Use Google Webmaster Tools URL removal tool to request removal of information on a page from your website
To use this tool, you only need to submit the exact URL of the page (you won't need to specify any removed words). Once your request has been processed, we'll remove the snippet and the cached page from search results.
Note: Google indexes and ranks items based not only on the content of a page, but also on other external factors, such as the inbound links to the URL. Because of this, it's possible for a URL to continue to appear in search results for content that no longer exists on the page, even after the page has been re-crawled and re-indexed.
Removing non-HTML content
If the changed content isn't in (X)HTML (for example a Flash file or PDF file has been changed), the fastest solution would be to change the URL of the file so that the old URL returns a 404 HTTP result code and use the URL removal tool to remove the old URL.
Proactively preventing the appearance of snippets or cached versions
You can use the "nosnippet" robots meta tag to prevent showing of a snippet, or the "noarchive" robots meta tag to disable caching of a page. Note that if this's changed on existing and known pages, Googlebot will need to re-crawl and re-index those pages before this change becomes visible in search results.
Note; google don't recommend this as a default approach," google explains.
[Source: Google Webmaster Central blog]