To edit any part of a feed – keywords, URL, name or description – click on the "edit news feed" link next to the feed’s description on the main News page.
To remove a feed, go to that feed’s page by clicking "see more" from the main News page, and click "Delete news feed" in the upper right of the page...
... or click on "edit news feed" and then on "remove the news feed" in the Edit News Feed dialog.