How to remove unauthorized links from Google's Search results?

Google provides users with a form to report suspected copyright infringement here: https://www.google.com/webmasters/tools/legal-removal-request?complaint_type=dmca.

You have to fille the form with the following informations:

• Contact Information
• Identification and description the copyrighted work
• URL where we can see an authorized example of the work
• The location of infringing material (URL List)

How long does it take for my request to be processed

We remove search results that link to infringing content in Search when it is brought to our attention, and we do it quickly. Our average processing time across all removal requests submitted via our web form for Search is approximately 6 hours. However, many different factors can influence the processing time for a particular removal request, including the method of delivery, language, and completeness of the information submitted.

Google is very reactive about requests to remove URLs from its search results due to copyright infringements.
Your request must simply be clearly justified and include the required information.

Remember that it is important to save your list of unauthorized URLs before asking Google to remove them from the search results.

Once the pages have disappeared from Google's search results, they are still online and accessible to visitors, so it is important to have this list available to make your DMCA takedown requests.

Google statistics on deletions due to copyright infringements are available here: https://transparencyreport.google.com/