To add a Light Source, go to the Render workspace. If you've just opened a file, you'll be in the Design Workspace, just click on the top left dropdown where it says "Design". Click on Render.

Now you're in the render space, click on the lightbulb Icon.

A set of movable manipulators should appear near the origin of your part, see how these change the values in the command window to the right? I suggest you play around with these and see what they do!

You can choose your light source size, its distance from the origin, and its orientation in 3D with the two angle values. The bulb type can also be changed, right now there's two options - 1500 lumens and 800 lumens.

Once you click OK, your LightSource (a white circle) should appear facing your part. If this isn't in the right place - hit Ctrl-Z and try again!

Now these don't do anything in the normal model view, to see what effect it has, hit the "Render in canvas" button, or the "Render" button. I suggest you render in canvas to preview what it's going to look like.

You can add as many LightSources as you want. Once you're happy with your perfect part, beautifully rendered - hit Render!

The installer that ran when you downloaded this app/plug-in from Autodesk App Store has already installed the app/plug-in.

OR, simply double-click the MSI to install the app.

You can unload the add-in without uninstalling it by clicking the "Stop" button when the add-in is selected in the list box on the "Add-Ins" tab of the "Scripts and Add-Ins" dialog.

Unchecking "Run on Startup" causes the add-in not to be loaded in future sessions of Autodesk® Fusion 360™.

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, you can uninstall it from 'Control Panel\Programs\Programs and Features' (Windows 7/8.1/10), just as you would uninstall any other application from your system.