First of all, please note that Google isn’t the only search engine out there and it isn’t the only search engine that uses cached copies of pages. Also be aware that if you don’t take care of the offending cached copy soon enough, the information may be cached in the Way Back machine, which is an Internet archive. Getting them to delete something is a whole other ballgame.
That being said, if you want to get a cache updated or removed from Google then you need to follow these steps:
2. Use the “Web page removal request tool” ( https://www.google.com/webmasters/tools/removals?pli=1 )
3. Enter the URL that you’d like to remove (case-sensitive) – This section is tricky. Make sure you provide the URL for the page as it appears in the search results from Google.
For more help with this requirement, read this article (http://www.google.com/support/webmasters/bin/answer.py?answer=63758)
4. Provide a reason: Most likely you will select “Content has already been removed from the page”
5. Enter the term that has been removed from the page – This is the term or terms which currently result in Google displaying the page which you wish to have removed. It’s vital that the search terms do not match to any part of the corrected, live page or else your removal request will likely be denied.