How to change an owner?

Hi,

We have changed our organization's official email address from Xtra to Gmail domain.

The previous email addres (Xtra account) was an owner, and Gmail address is an Administrator.

We would like to make GMAIL the owner, and we want to downgrade Xtra email to Adminstrator.

How do we do that?

Thanks,

Tatjana Injac

Secretary

Raroa Afterschool Committee