You can change your Ebook settings and contact info in Your Profile page.
Login to backoffice.
Click on Settings on the left menu of the main page.
Click on Websites > Free eBook Personalization.
Update your contact info as desired and hit 'Submit' at the bottom of the page.
Note: There is limited space as to what can be shown in the Contact information boxes on the ebook, so be sure to read the notices to the left of the boxes.