when u start a dynasty, all the draft picks the the next year are in players.dbf, just change the names and stats of those players, just that ez....and of course if patches are made, just add the id7 and plyrpkg abbreviations to that players and they'll look like the guy too
You can create them before you start your Dynasty and when you start it, they will be able to be drafted
Fantasy Draft or just sign them
I dont know if it is possible to do after you start