Shadow Analysis Exporter can be found in the Addins tab. In the main window, you can choose which families will be included in the exported model. Families are divided into two lists: 'Default families' and 'Other'. The Default families list contains categories of elements which are most commonly used in Shadow Analysis. After the selection, a new custom 3D view will be created, showing only chosen families. Now you're ready to export it. Go to main Revit menu and choose Export -> FBX. Please make sure that the selected file format (Files of type) is "FBX 2015 and Previous".

Detailed instructions can be found at http://deltacodes.pl/ShadowAnalysis2_Exporter_for_Revit-help. 

The installer that ran when you downloaded this plug-in from Autodesk App Store has already installed the plug-in. You may need to restart Autodesk® Product to activate the plug-in. To uninstall this plug-in, click Control Panel > Programs > Programs and Features (Windows 7/8/8.1/10) or Control Panel > Add or Remove Programs , and uninstall as you would any other application from your system.