The gold standard for academic watermark removal used to be (and maybe still is?) https://github.com/kanzure/pdfparanoia https://github.com/kanzure/pdfparanoia

The gold standard for academic watermark removal used to be (and maybe still is?) https://github.com/kanzure/pdfparanoia https://github.com/kanzure/pdfparanoia . Not sure if it edits Elsevier's metadata though.