1. Run the tool 
2. Select to run on selected lines or on entire project
3. Select the floor type
4. Click OK.

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.

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) and uninstall as you would any other application from your system.

Occasionally, the selection option "Entire Project" may not execute & won't give any results, but the other option "selection" does execute properly & gives proper results.

If you are faced with any such issue kindly report with the scenario.