Okay, after you extract to the flash drive, start the ps3, and on the dashboard or whatever it is called, you find the roster file and copy it (should go directly into the place it needs to be)
Start the game, and first thing, go to rosters and save, creating your own save name.
Then, load the OS rosters (should be called OpeningDay)
After they load, save them over writing the roster you saved earlier.
Something with the writing makes it unable to save the rosters in game if you load the OS rosters, so when you start your franchise/RTTS, load the roster you saved under your name.
I recommend you just run though it once without wasting time on making your guy, just to see if you did it right, and just exit and restart your rtts if you've got it down.