Steps for transferring a Brand Account YouTube channel
After ordering your monetized channel we will send an invite to the email that you used when ordering.
The new owner (you) must accept the invitation.
Wait 7 days. Google commonly requires this security waiting period before making someone the Primary owner.
After 7 days, go to Manage permissions on your brand account.
Change the new person from Owner to Primary owner.
After you become Primary owner, you can remove the old owner if needed.