Switch to Addins (or Plugins) tab, then click the app's button. Command PlineClosureReport will run. Then, first step, you will be asked whether or not to change the current closure distance tolerance. Secondly, you will be asked to pick a polyline. A Closure Report will be created and shown in Text Window. Finally, you will be asked to enter the file name to save the report. You can press esc to skip. If you enter a file name, a text file will be created and saved to the current drawing's folder.

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. 

On Windows 10 Version 1703 or later press Windows+I on the keyboard to access Settings or click the lower-left Start button on the desktop to expand Start Menu and then select Settings in it. Click on Apps. On older versions click Control Panel > Programs > Programs and Features or Control Panel > Add. On click Control Panel > Programs > Remove Programs.