I want to look at certain mechanics to understand how epic did them, is there any way to unpackage the c++ classes or bps?
peeking into Fortnite Source is not possible if the game is compiled, you can only peek binaries in debugger.
i can’t add code to show the scripts?
unreal has encryption options. You may not even be able to look at the binary 
There is probably encryption added to prevent cheating
also, what good it will be? What do you want to see? The real deal part of the code runs on the servers, you can’t see that. You can’t download those binaries. On client there is only the movement, animation, stuff like that
Yeah i’d like to see how they did the new grappling and sliding, I’ve lost braincells trying to add sliding to my game