To update an idea, select that option from the right side options menu.
This takes you to a page where you can make your changes and, when finished, click the "Update Idea" button.
To delete an idea, that option from the right side options menu.
This opens a page that lists the idea and asks the question "Do you want to delete this Idea?" If the answer is yes, click the "Delete" button at the bottom of the page. If not, click "Cancel."