On your Zankyou website, clicking on the button 'edit' in the top right hand corner. 

On your website you will have two options.

Design: This section of your website is the visual part of your website. You can chose your favourite background, edit it and design your own space from start to finish.

Edit: This section includes all the content of your website. Edit your website and gift list / registry, add gifts and new tabs as well as information, edit exts... anything you want.