Hi there, chill water dan.
As mentioned by my colleague above, you'll first need to invite the new master admin. Then, give the user a temporary company admin access. That being said, as part of the process, you'll have to enter their information including the email address of the newly invited user.
Once the newly invited receive an email, they need to accept the invitation. Then, let him/her select “Let’s go!.
After that, go the Manage user page and look at the new invited one and click the drop-down arrow under Action. Then, choose Make a master admin.
For additional information on how to transfer or change who manages your books, you can check this article: Change your QuickBooks Online master admin user.
Please refer to this article to see the different user types and levels of access in QuickBooks Online: User types in QuickBooks Online.
Let me know if you have any other concerns, I'm always here to help. Wishing you and your business continued success.
