You want to remove (unpublish) a project that has been published by Workflow (any version). Note: This article is applicable to Workflow and ServiceDesk, as ServiceDesk uses Workflow projects.
Follow the below steps to remove a Workflow project. Note: If these steps are performed on a ServiceDesk server, substitute the paths "<Workflow_installation_drive>:\Program Files\" with "<ServiceDesk_installation_drive>:\Program Files (x86)\"
If these steps were performed to remove multiple versions of a project, specifically for ServiceDesk, minor issues may occur with old tickets that were made with the removed version of the project. This can occur, for example, if SD.IncidentManagement was customized and saves as a different project name. These sort of issues can usually be safely ignored; all new tickets made with the single version of the project should work correctly.
Versioning is discussed in the ServiceDesk Customization Guide starting on page 14.
Altiris Product Guides
How to restore a ServiceDesk Workflow project to its out of box version after it has been customized