How do update already published VSP Engine Tools?

The POST installer can be updated any time through a newer version without uninstalling a previous version. The VSP Engine Tools on your ArcGIS Server can also be updated by defining the name and the server folder of the existing VSP Engine Tools, which should be updated. If you choose a different folder and/or name, additional VSP Engine Tools will be published. For VSW applications you have to choose the Printing Service URL pointing to the desired VSP Engine Tools. The VSP Designer will use the VSP Engine Tools with the latest update timestamp automatically.