Troubleshoot: Changing SIS ID in Canvas
For whatever the reason, you needed to delete the course shell/users and re-create them again. But Canvas does not let you do that because of "SIS ID already in use" error. This article walks you through to change the SIS ID in order to re-create something that existed.
In Canvas, even if you delete anything, it is not exactly deleted. This is problematic when by accident you delete courses/users and you need to re-create them with the same SIS ID.
Here is the template that you can use: All-in-One TEMP for Canvas
Modifying Change-of-SIS ID file
You simply have to change the SIS ID to something else via SIS upload. Then you will be able to use the original SIS ID.
In this actual case, I've accidentally invited new user before creating the user account in Canvas. At the same time, I've created the user account without knowing the user had already signed up by themselves. In order for me to re-sign the SIS ID for the account that they created themselves.