References names are missing


I was wondering how to fix this issue if it’s possible at all to do. I’ve imported A LOT of articles into Endnote and created a library. The problem is that most of the articles pdf’s have no full name on it. Now I have thousands of articles named according to file name (which is 6 digits). So, is it possible somehow to change all file names (therefore and reference names) automaticaly or extract if from the file to have a perfectly functioning library??

Thanks A Lot!