From Valve Developer Community
Warning:At this time, the Dota 2 Item Tools are in active development - some features may be missing or incomplete.
An overview of how to create items for inclusion in the Dota store.
See also: Dota 2 Workshop Info (NOTE: Some of the information on this page is Source1-specific and will be updated soon.)
- Install and launch the tools
- Select "Launch Item Tools"
- Select "Create New Item" to select your files to preview and upload, or select an existing workshop entry from the list to update it.