Pdf to word data conversion work

Have a 400 page draft technical (engineering) reference manual that describes rules for energy calculations. Document is a locked pdf. This document needs to have cross references added for "changes" that were accepted by the authors.

But the accepted (and rejected changes) are in a 3 volumes of "scanned pdfs that are not searchable. (about 4000 pages). There are 338 comments. about two thirds were accepted. these are refer to page numbers of the draft document.

My goal is to only have to look in one place for the "rules" instead of 4.