How do I transfer ownership of my endpoint for billing purposes?

There isn't a way to do this at the moment, but you can do the following to achieve functionally the same thing:

1. The owner of the endpoint you want to transfer does a server backup on their endpoint. (Read more here.)
2. The new owner creates their own instance.
3. The original endpoint owner sends the server backup to the new owner.
4. The new owner does a server restore with the backup on their new instance.