I'm using Nintex Workflow for Office 365.  I have a workflow that creates a subsite from information in a top level list.  There's a status field in the top level list that's a choice field.  When a new subsite is created via the workflow, that status field is set to "Active".  At any point, a user can change that status field to "Closed".  When the status is changed to "Closed", I would like for the subsite to be read only, meaning all access to the subsite is set to read only.

I believe you can do this manually, but I'm needing to do this via the workflow.  Does any one know how to accomplish this via a workflow?