To change the size of your project as well as the cover option, simply select the book icon in the top right toolbar.
After selecting the new product, Mimeo Photos will reformat your existing project and images to the correct sizing and dimensions. The new price of your project will also be updated and displayed.
It is important to keep in mind that changing the product may effect some layouts and customizations.
In the case that you wish to switch back to the previous size product, the undo button will provide the option to revert changes.