Thank you for reaching out to the Community and welcome.
If you want to remove a collaborator from a Collaborative playlistyou just need to tap the profile pictures under the playlist name and edit the user you want to remove. You can find all the information related here.
In case that the issue is not with a Collaborative playlist, but a Blend instead, you can leave the blend with the steps listed in this article.
Hope this helps. If you have any additional questions, don't hesitate to ask.
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