Check out to get video manual: https://youtu.be/zoVv3uHy-JI

You can see details in pdf file here: "C:\ProgramData\Autodesk\ApplicationPlugins\ALB_CropView.bundle\Contents\Resources\Help\Alpha BIM - CropView Guideline.pdf"

Steps to use Crop View add-in:

1. Active a 2D view or 3D view on Autodesk® Revit® document. This add-in can’t run on the Family environment.
2. Click the Crop View button on the Alpha BIM ribbon to run this add-in.
3. Drag the mouse to define the region of crop view or press ESC to finish.

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.