After you have created your organisation and reporting sites to NordSafety, you can still edit them.
Start editing by going to domain tree and pick up the branch you want to edit. Activate it by clicking on it and also activate the editing mode by clicking the yellow "Edit" button. You are now free to edit nearly all of the fields on the form.
The only field you can't edit afterwards is the "Reporting site" field. If you need to change it's status, you just create a new domain. Remember to remove the unnecessary domains from your tree.