Hi,
If your old page url that are currently not available is showing up in Google search result page and you don't want them to come up in search result page means you want to remove them form search result page/Google for this you have to perform the following steps.

1. Log in to webmaster.
   Direct link for webmaster- https://www.google.com/webmasters
2. On left Menu click on Google Index==> Remove URLs.
   
3. Just right to this you will find Create new removal request button click it, and enter the url you want to remove and click continue.
4. This will take to to next page where it will ask you the reasons you you want to remove the url, select the correct reason and click submit request.
Best is to select remove page from search result and cache, for the reason as this will permanently delete your url from search result page.