i've helped migrating a few accounts from facebook to legacy and then to ubisoft (with also getting the gift pack for doing so)
i had to have under facebook an email address that hasn't been used on TSO.
once that was done, i've cancelled the facebook link
after 2-3 hrs i've received a pssword setup email
and there i was. the game account that was under facebook login was migrated to an unused new legacy account (username was the email under facebook)
as legacy won't be used much longer i suggest you use a random email .
after you have legacy sorted, you have to migrate it to UBISOFT
once again, if you have an UBISOFT account that has a wrong level game account in , you have to delete it and wait 2weeks till it's done .
but if you want a quick migration to ubisoft then:
1. login to legacy where you have the game account you've played on recently (the one you've migrated from facebook to)
2. go to my profile and click migrate
3. AND NOW IS WHERE IT CAN GET COMPLICATED OR EASY
if you create a new ubisoft account under the migration process, then migration is done. you'll have the new ubisoft account with your game account linked up and ready to go
But if you wanna use an old ubisoft account, you then have to delete the game account that's under it, again 2 weeks time and then you migrate it in.
not confusing at all, is it?
Spoiler