Deleting a page is NOT recommended because it can cause significant issues with your SEO. But if you still want to delete that page, here's how - Open the page within the CMS, then select the Delete tab and follow the instructions.
You have found the directions, but before you do delete that page, consider - if anyone has linked to that page, they will then get an ugly page not found message and may go elsewhere rather than visit the rest of your site.
To avoid this you can "hide" the page so that most visitors won't see it (instructions here), yet those arriving via a link to that specific page will be able to continue browsing your site. You can even replace that pages content with a "page moved here" or "our replacement product is here" message