Wait.. you signed up twice?
Don't need to. The 'signup' button on the main page sends the details to create the 'my health' acct. If you signed up on the beta, you just use those details again!
Mine was browser saved, so all I had to do was change url and hit the login button. It hands off to login.health.nz and if you were on beta, still verifiable.
/edit nevermind.. I see now it was a 2nd person.
Did you see the big fat banner saying the legal implications for doing it for someone who wasn't you :)