- Sign in to your YouTube account.
- Click your account icon in the top right corner of the page.
- Click Creator Studio > Video manager > Copyright notices. Here you will be able to see any claims that you may have.
- Find that claim you wish to dispute and click the copyright symbol next to the video. This will provide information regarding the claim and which content in your video that it refers to.
- Click File a dispute and follow the steps.
For more information, please see: https://support.google.com/youtube/answer/6013276