Create a new app using the "Siemens DISW UI Library" and export and import the marketplace modules that differ between the two. Then go to the application's app directory (Menu: App -> Show app directory in explorer) and swap both the directories 'theme' and 'theme-source' from your new app to your first app. With any luck you will not run into too much errors, but likely there will be failing classes on page-objects. See how far you get and if it is worth the effort.