Update Published Visual Studio workflow

To update workflow that is already published need to have versions, to do so follow the following 

http://turtlellc.com/sharepoint/sharepoint-workflow-versioning-with-visual-studio-2012/

http://blogs.msdn.com/b/yardman/archive/2010/04/14/versioning-a-visual-studio-sharepoint-workflow.aspx

https://social.msdn.microsoft.com/Forums/sharepoint/en-US/0f50841d-e9ce-42a5-b489-45575463bb56/sharepoint-workflow-versioning