You can add and remove photos and video clips in a shared photo stream that you created. You can also update items in a shared stream.
Select the items you want to add to a shared photo stream.
Do one of the following:
Click the Share button in the toolbar, click iCloud, and click a shared stream.
Click the Add To button in the toolbar, click iCloud, and click a shared stream.
Drag the items to iCloud in the Source list, and click a shared stream.
Type a comment if you want, and click Publish.
Select iCloud in the Source list.
Double-click the shared stream containing the items you want to remove.
Select the items you want to remove and press Delete.
If you share a photo or video in a shared photo stream and then make edits to it, the newly edited item doesn’t automatically appear in the shared photo stream. You can either add it to the existing photo stream along with the older version, or you can delete the older version and replace it with the updated item.
Select iCloud in the Source list.
Double-click the shared stream containing the item you want to replace.
Select the photo or video you want to replace, press Delete and then click Delete in the dialog that appears.
In the Source list, select Events, and then double-click the event containing the updated item.
Select the updated item.
In the toolbar, do one of the following:
Click the Share button, click iCloud, and then click the shared photo stream that contained the item you want to replace.
Click the Add To button, click iCloud, and then click the shared photo stream that contained the item you want to replace.
Type a comment, and click Publish.
The updated photo or video replaces the item you just removed.