A relative has added me to her shared photo stream. Of course, when I receive photos, I "like" them and then save only the ones I REALLY like. However, my phone is slowing down and I figure it might be all the photos. Now I have over 600 photos that I DON'T want... how can I delete them without affecting the stream she set up? I have a iPhone 5 running iOS 9.3.4. Thanks very much in advance.