Interesting, Thank you very much for the reply and the information! I hate to bother you with another question, but would you know where I could go and learn how to do that? It's something I am really interested in. Thanks in advance!
I was not able to found too much info for this readily available on internet. You can get as far as extracting all files from the game with tools from (free) UE4 editor (assuming files are not encrypted), but after that you have serialized blueprints which are not human read-able or importable to engine without some modification. I do not exactly what these modifications are, nor I know where you could find such info.