1. Click the Grid Line button in Add-Ins Ribbon Tab. Or write GRIDLINE in Command-Line and press Enter.   
2. Specify the first point to draw grid line with default parameters, or select a keyword for changing parameters.
3. Specify the second point of the grid line.
4. Repeat these steps for each grid line.
5. Press Escape or Enter to cancel the command.

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.