You have the possibility to edit a schema afterwards. Double click on the desired schema. On the left side you will see the individual options. You can switch between them by either directly clicking on the particular topic or by clicking on the blue arrows below:

 

 

You also have the possibility to copy a selected schema. Just go on the Copy schema button:

 

 

A second schema will appear that has the same name like the first schema but with a (1).

 

Lastly, you can also delete a schema. Select the desired schema with a double click and go on Delete schema:

 

 

The following window appears:

 

 

If you are sure you want to delete this schema go on Delete. Otherwise click on Don't delete.