If none of the previous steps worked: the infringer could not be found and contacted or refused to remove the content, the domain owners/admins were irresponsive or refused to comply, the hosting provider refused to take action, there is the last step to consider. Google delisting means removing the Google link to your copyrighted content, so it is not possible to find it on Google.
This step is an extra step if you want to do something about the situation, but it is not as good as previous steps and the outcome is a bit different. On the previous steps you can actually achieve the best outcome – the full removal of the reported content (and maybe even ban or warning for the uploader). In this step, the content is still there and available for domain visitors, however you are making it more difficult for people to find it on a search engine.
There is no specific message sent to Google, but you need to fill the form here:
https://support.google.com/legal/troubleshooter/1114905
Choose Google Search as a product and pick the option: Intellectual property issue / Copyright infringement / Yes, I am the copyright owner and then complete the form and create a request.
If you can provide the requested information, Google will take action and remove the link to the reported website from Google search engine results.