We’ve added a self-service feature for organization owners in Shopify Plus to transfer organization ownership to other users within their organizations without having to contact Shopify Support.
As an organization owner, you can navigate to your own user profile page in the Shopify Admin, click "Transfer ownership", and follow the instructions on the screen to complete the transfer. You can find more information about ownership transfer in the Shopify help center.
Note: this feature only allows you to transfer ownership to another internal user within the organization. To transfer organization ownership to external parties, you still need to contact Shopify Plus Support.