Changing a linked account to a new origin account

For an account problem like this one you will need to contact a Game Advisor at EA Customer support:  https://help.ea.com/contact-us I advise to have your friend with you so he can validate that he authorizes this change to his Origin account and he can answer his security questions.  Be prepared to answer the security questions for your Origin account too.

1 Click on the following link: https://help.ea.com/contact-us
2 Make sure you are flogged in (top right corner)
3 Click on the blue button "Contact a Game Advisor"
4 Enter the name of your game or product (or "Origin" for account-related issues) and click "Find Solutions"
5 Select the type of issue and the platform you play on, and click on "Find Solutions".
6 Click on the blue button "I still need help" if the FAQ articles do not apply to your situation.
7 Select a contact option. Note that you may get different contact options depending on your country.

I recommend that you use the telephone option and the “call me” option so you don't have to stay on hold for a long time (call back feature available to North America only).