Filing a Digital Millennium Copyright Act (DMCA) takedown notice on YouTube is a formal process to request the removal of copyrighted content that has been uploaded without your permission. To initiate the process, you'll need to go to YouTube's Copyright Complaint Form. After logging in, you'll be guided through steps to identify the infringing video and provide evidence that you own the copyrighted material. You'll also need to provide your contact information and affirm under penalty of perjury that your claim is accurate. Once the form is submitted, YouTube will review your claim. If it's verified, the platform will remove the infringing video and may issue a copyright strike against the uploader's channel.