Once you have unlocked your desired photos, check the box on each photo and click the Export button at the bottom right of the application. 

The application will ask where to save your photos. The easiest option is to save to your desktop. From here you can save the photos to a CD or USB and take them to be printed at any photo retailer.

Need further help? 

View the below videos for Mac and PC that show this process

Windows installation

Mac installation