Please refer my previous article to learn more about creating NINTEX workflow.
We will be deleting a content type from SharePoint list by calling the web service _vti_bin/lists.asmx.
Workflow Design:
Web Request Action: 
Soap Action: 
Result:
Content type is deleted successfully from SharePoint list.
Jeni RajaPosted Jul 15, 2015, 5:49 AM
This is nice. Very useful and informative. I will refer to this during my next SPUG on Nintex and of course give credit Eric Rhodes for putting this together. http://www.trainingintambaram.in/php-training-in-chennai.html