The text editing is very straightforward and uses the same system as editing a Microsoft Word document, with all of the same functions (such as bold, italic, left-aligned, center-aligned, etc.)
You can edit any of the text, and hit "Save" at the top right when you are done.
Once you save a page, you can open up your browser and go to the page you just edited. The new changes should be updated. Simple!
Here is a quick video to show you some of the features of the text editor.