I read somewhere that the 'copy over option file from PES 2011' option is in again this year, I only hope it works better than last year for 'division 2'.
It would take a bit of time (but not as long as editing the players one by one), but I had an idea of how to bring over everything appearance-related about players that you've edited (not default scanned faces) into the new PES. (Sorry if this has been talked about before)....
- Use the 'copy over option file from PES 2011' option
- create a BAL game using each of the players you want to keep
- Go into the edit mode and revert the edit data back to the PES 2012 default again
- export each of the players from your BAL games into the created players section
....if you were doing it for every player in the Birmingham, Blackpool and West Ham squads it would take a long time, but it would still be quicker than editing the players one by one.