I have a very large PDF that is a bunch of pages broken up that will be printed then cut and assembled into a large prop for a costume. The PDF was created in such a way that the images add up to a specific height when printed out and assembled. You can see an image of the PDF with the images broken up on it here:
I want to make it double sided by flipping the PDF horizontally (mirroring the images), re-printing/assembling, and then affixing to the blank side of the first copy of the prop.
I already have a properly scaled PDF for the first side, so that when printed and assembled, the prop is the proper scale. I no longer have access to the original image used to make it so I can't flip the image and try to make the same PDF over again but mirrored.
How do I flip my already existing PDF horizontally to achieve my goal?