To edit an existing page, click on the Edit this page button in the CMS toolbar that sits on the top of your website pages.

The edit screen will pop up in a new browser window. To switch between views, click on the Page content and Main summary buttons in the CMS toolbar.

Click on the Save changes button to save your changes. You should then see a confirmation message and when the window closes, you should see your page displayed in your site's Template with the changes you made.