Batch replace multiple logos across multiple PDFs

@Eliot28211083f87q 

Do you have access to original INDD files - to re-export PDFs?

Are you asking about editing the InDesign files that were used in creating these PDFs? Or are you asking about editing PDFs directly in Acrobat? You're in the InDesign discussion area, so if you have the native INDDs, then we can teach you how to relink files and make fresh PDFs. The capsule version is that logos should be separate files that are placed and linked, so you ought to be able to use the Window -> Links panel to find and replace them all. Let us know if you want step-by-step instructions. 

But if you're talking about the Watermark feature, then you're most likely asking about how to edit these PDFs in Acrobat - in which case the Acrobat discussion group is thataway. (And no, it's most certainly not the intended use of the tool, but sometimes the wrong tool is the only one you have. You have other options here, but honestly Watermark might be your least-bad option.)

Lastly, the process of editing PDFs in Acrobat can occasionally be smooth and easy, but usually it's neither. If you have hundreds of PDFs, and no native files to edit, I strongly suspect that at least some of them will be a huge time-sink. The hassle of trying to find the original source file might feel like a waste of time, but e.g. once you get to PDF number 57 that is completely un-editable and needs to be recreated from scratch, you will very much appreciate that the time spent sending emails saying "Hey, your name shows up in the Author field of the PDF properties for PDF number 57, can you please send me your source file?" and think of that time as Time Well Spent.