If you wish to reorder the pages of your flipbook just follow these steps:
Step1. Open PubHTML5 and import your PDF or image file.
Step2. Click on the "Animation Editor" button on the top toolbar.
Step3. Select the page you wish to move. Drag it to the place you want, or make use of the "Move Up" and "Move Down" buttons.
Step4. Click the "Save And Exit" button on the top-right corner and you're done.