Delete previous versions of Nintex Forms

Instructions

You can see all Nintex Forms in the site from the URL http://<YourSite>/NintexForms 
Select item, click ellipsis and go to Versions History for the form you want to delete. 
In the Version History screen,
- Click the link "Delete All Versions" - You can delete all versions except the latest published version 
- Click the link "Delete Minor Versions" - You can delete all minor versions

 

Additional Information

You can identify the Forms by using NWAdmin tool (ResolveSharePointIds)