I'm going to give away my PS4 which has a saved file that my friend and I worked hard on
Why don't you back up the save?
I'm giving them to another friend to play with
I think that you should make sure that your first friend is okay with it, too. You should not give it away unless both of you agree on it.
My friend would agree to this.
It's good that you are ready and willing to share your possessions with another friend.  I'm sure this third party will enjoy the system as much as the two of you did.  However, if sounds like you are just guessing at what your first friend will say, so make sure that he or she explicitly allows for the saved file to be given away.