Help regarding linking of PS3 and SE accounts.

Hi,

I've bought FFXIV and been playing it for the PC for a week now. I bought the game for my brother to play with me, but for the PS3 since he doesn't have a decent PC.

After installing he wasn't paying any attention and registered his code (with his SE account) while logged into my PS3 account - only noticing it would link the two when it came up with the big warning at the end. He reset at this point and tried logging into his PS3 account, but it is now telling him that his code has been used already.

Was wondering if you could advise about how to get his two accounts correctly registered?

Thanks.