Change page size for 40+ page document InDesign CC

I have a 40+ page document in InDesign CC in German A4 document size. I need to change it to a US Letter document and adapt the design to the US Letter size. 

Is there a way to change the layout for all pages at once?  Important: this is a product catalog, all graphics, texts, objects have already been placed,  but to fit the narrow A4 page margins. 

Every attempt I made I had to reposition every object, table, graphics, etc. manually on every page.