iBooks Author: Create a new template
You can modify the elements of any template to suit your needs. If you want to reuse a modified template in the future, you can save the template so that it’s available in the Template Chooser. If you want to save your template without having it appear in the Template Chooser, you need to save a document.
Save a template to the Template Chooser
With the template you want to save open, choose File > Save as Template.
Use the default location and click Save.
Delete a custom template from the Template Chooser
Click the Finder icon in the Dock and choose Go > Go to Folder.
To open the Templates folder, enter:
~/Library/Application Support/iBooks Author/Templates/My Templates/
Find the custom template and drag it to the Trash.