I did come across this video on YouTube where someone goes through service mode menus of the Odyssey.
How can I get to those menus?
You enter service mode by first switching the Odyssey off and then back on while also pressing left and right button (those on the sides of the Odyssey, normally used for page flipping).
I would select a different book than you are reading first, because it is easy to loose your current page if pressing both keys is not recognised. If only one is recognised, you start scrolling through your book and loose your last reading position.
Be careful what you try in the service menu, there are some menu entries that reset the internal memory, SD.
You can go through the menu by using the left button for up, right for down and front button for select. Go up (left button) all the way to the top for the parent menu entry.
(not sure why the poster of that video did not include this info on youtube)