How to remove myself from shared cards that I’ve joined

Thank for your quick reply @tobias! Sorry for not clarifying this before maybe ‘import’ was the wrong wording. I imported them with links from other users, hence I was just a ‘Reader’.

I have attached the two screenshots. After taking the screenshots I indeed tried to delete each card individually and it worked, it disappeared and also the count went down. Let me update the question quickly, yesterday I removed the parents cards from the ‘Outline’. Is it possible that the children remained out of the ‘Outline’ but still on the ‘Home’ tab? Is that expected behaviour? To remove a parent and the children to stay around?