Unfortunately (or fortunately for security reasons) only the current account owner of the Zendesk instance can transfer ownership to another user. Please follow these steps to change owners...
To transfer ownership to a current administrator
- In any product, click the Zendesk Products icon () in the top bar, then select Admin Center.
- Click the Account icon () in the left sidebar, then click Account owner.
- Select an administrator from the Account Owner drop-down list. You must have at least one other administrator to see the list.
- Click Save.
Let us know how that goes and if you have any questions. There's a Zendesk article for more information about change of ownership here if you need it: https://support.zendesk.com/hc/en-us/articles/360002095848-Changing-the-account-owner#topic_ubp_zq5_w2b