Unable to re-edit an old design

Hi!

I recently got a job to modify an existing PCB. However the design is so old, we don't have the database file used for it, thus I can't do a forward annotation. Is there a way to modify such designs? I would have to add some components too, I can modify the existing routing, but that's not necessary. I've attached some pictures for better understanding.

Thanks!!
Best regards!
Laszlo