This set of instructions applies for Team Pro accounts only.
It's easy for an account owner to transfer ownership via the G Merge Plus web app. Simply log in to:
The new owner should already be an active team member, as shown:
If the new owner is not a team member yet, here are the steps to add the user:
On the Users page, click on the new owner's name to open the sidebar. Click on the "TRANSFER OWNERSHIP" link, as shown:
Confirm the transfer on the pop-up message:
Note: By confirming the transfer, the current owner's role would be automatically set to Manager.