You can edit
or delete a shared page, portlet, application, link, or syndication
channel only if you are a group content administrator for the group
with which the item was shared.
When you
edit shared content, the changes that you make appear in all of the
users' portals where that content is displayed. When you delete shared
content, the content is removed from all of the users' portals where
that content is displayed.
Users
who are not content administrators cannot edit or delete shared content.
For detailed
instructions on deleting, see the following topics: