Go to the eCreator course you would like to edit (if you're not already working on it) and make sure you have clicked on the Pages tab (see view an existing eCreator course if you're unsure how to do this).
Scroll down to the bottom of the page and click on the X link next to the page you'd like to remove.
Click on Yes within the popup window.
The page will be moved to the Removed Pages section at the bottom of the Details and Pages screen.