I'm using Linux (Pop_OS), so I'm not sure the info below is that helpful, if at all, under Windows. The tools are the following:
poppler-utils (specifically pdftocairo to convert the PDF to .jpg files), and then imagemagick (to convert the image files to a full PDF again).
Here are examples:
pdftocairo -jpeg ThousandYearOldVampire_SinglePages.pdf "[path to new folder containing output images]"
convert [above path]/*.jpg [destination/ouput].pdf
I'm not sure it's the simplest way to go, but at least it works.
I could just send you the files I've made this way? I haven't double-checked them but they look OK.