1. go to https://www.google.com/webmasters/tools/home?hl=en and sign in with client’s google account. You may need them to authenticate if you have never used the account before
  2. Click on the site that you want to remove a URLs from
  3. Click on the dropdown Google Index and go to Remove URLS
  4. Click on “temporarily hide” and type in the URLs you want to hide.

Technically Google can only temporarily remove these for up to 90 days.  After that they can reappear.