Login to Admin Mode, go to the page you want to change, and hover over its "Page:" link near the top of the page. This will cause the Page Menu to be displayed. Click the "Edit this Page" link on the Page Menu.

You may update the Short Title and/or Long Title values using this form.

Short Title: This is the name that will be used in your site's navigation or menus to represent this page. Enter a short, mixed-case name for this page (e.g. "Contact", "About Us", "Products").

Long Title: This is included in the page's overall title along with the Site Name and the Short Title. The page's overall title is: (a) Displayed at the top of the web browser window when a user is viewing this page, (b) the default name for user bookmarks or favorites, and (c) is used by search engines to determine what this page is about and to assist with its page rank determinations. In order words, the page's overall title is composed of: "Site Name - Short Title - Long Title"

Click the [Save Changes] button to update the page.

There is more information about each of the above fields in the "Add a New Page" entry.