The Unload IIS Application actions allows you unload a given IIS web application from memory.
Select a web site, as per the Website Selection tab. Choose "update automatically" to have the virtual directory list automatically update as you change web sites.
Choose the virtual directory which hosts the application that you wish to unload. You can set the action not to fail if the application is already unloaded.
Select "Recursive Unload" to recursively unload applications in all child directories.