After you have made a process official, you may want to make changes to it. This article explains how you can achieve this.
Go to Objects > Business Process and find the official BPMN view that you want to replace. Open the view.
Make a copy of the view using Save as.
Update the view.
4. Delete the current official BPMN view by clicking the cross sign next to Official. It will automatically get the status 'published'.
Now you can make your updated view official. Right-click the updated view and click Set as official BPMN model. The last selected process will be made official.