Rename removable media in Catalog

I have Photoshop Elements 15.  My older router had a capability for attaching an external hard drive for network storage.  I have over 11,000 catalog images on that drive.  I upgraded the router to one by the same manufacturer but it is not backward compatible with the old storage capability.  In my old network the external drive was //191.168.1.1/My_Book.  The new router will not let me put the underscore character in the share name.  I now have 11,000 catalog items un-linkable to the removable media.  The manufacturer has referred the problem to their engineering.  It appears I will have to remove all 11,000 items from the catalog and re-import them.  Can someone suggest a better or a less labor intensive way than directory by directory?