I think the only option would be to call SE and have them unlink it from his account. The only other way I know of is to log into your SE account, which is impossible without the token. If he has all the original info linked to his account it shouldn't be a problem, I've had it done with my battle.net token before, took 2 minutes over the phone.
FFXI - Bruknar - WAR75 MNK75 BLM75 NIN75 SAM75 WHM75 DRK75 BRD75 RNG75
FFXIV - Bruknar Dinendal - Istory.