This editor is similar to a word processor on your computer. Highlight the text you want to replace with your mouse, and then type over the existing text.
To replace an image, right click on the image until a popup menu appears. Select "change image" from this menu and follow the on screen instructions. You can either replace an image from your computer, or select an existing uploaded image.
When typing in this editor, avoid using <enter> or <return> by itself. If you want a line break or carriage return, always press shift+enter or shift+return. This will ensure formatting and avoid any formatting errors. If something does not look correct, do not press save at the bottom of the screen. Cancel and start over. After your changes are acceptable, press "save".