Steps to use Cadsum STL Exporter for Revit:

1. Open your Revit model in an appropriate Revit version.
2. Click on the "Export STL" button in the ribbon bar and you will get a dialog with settings options.
3. Now click on the Export button and you will be directed to save dialog to select save file location.
4. Your exported model will be saved in the selected file location. View your exported model in the appropriate viewer.  

Steps to Activate: 

1. Click on the "Activate License" button in the ribbon bar. 
2. Enter the license key and press the Activate button. For license activation, the internet is required.

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.