What? Probably would find some help here if you could explain this a bit better.
You bought the PS3 version already? You should be able to just open open your old version and let the patcher update it. If not, just go into your Memory options and delete the game and re-download. Have not heard of a case where re-formatting is required.
If this is a question of accessing you old account, visit Mog Station and see what versions are attached to your account.
Edited, Jul 18th 2014 12:53pm by Gnu