You can download the Content Catalogue by opening Local Designs Gallery section of the Gallery on the right side of the program.
RIGHT click on each section you want to keep and click Download.

The content, once downloaded, is buried in the depths, and you need to be a blood relative of Indiana Jones to find it.
C:\Users\your user name\AppData\Local\Xara\WebDesignerPremium\17\Cache\designs\eng. You also need to have Hidden Files showing in Windows and look for the Xara name that suits your installation.

Click image for larger version.  Name: Astrid.jpg  Views: 85  Size: 33.2 KB  ID: 131066

Great minds and all that Acorn.