I have the SAU account, how can I split my projects into several accounts?

You can split your projects into different accounts. First, register your new accounts.
If you want to transfer an entire project:

1. Add the new account to this project's team
2. Make the new account the project owner
3. Reassign all your tasks to a new account (even the completed ones)
4. Remove your current account from the project's team

If you only want to transfer project tasks:

1. Add the new account to this project's team
2. Reassign all your tasks to the new account (even completed ones)
3. Remove your current account from the project's team

Don't forget about your archived projects.