To uninstall Silverlight on a Macintosh computer, first check to see if the plug-in has an uninstall feature. If you don’t find one, trying installing an uninstaller for the Mac OS such as AppCleaner or CleanMyMac. You can also find the plug-in itself, and delete it manually.
To make removing software more convenient, many manufacturers, including Microsoft, include custom uninstallers. These are the best choice to remove software entirely. Check to see if your installation of Silverlight came with its own uninstaller, including installation disks and images, and look for an option to install it. Free third-party uninstallers also do a fair job finding tiny bits and pieces of software, although they might not get all of the data files and directories.
In order to uninstall Silverlight, manually, first close all open web browsers to make sure that the plug-in isn’t running. Next, open the computer’s hard drive, and click on the Library folder. Open the Application Support folder, and look for Microsoft and PlayReady folders. If you find them, delete them, and empty the Trash. If you don’t find these folders, look for the "mspr.hds" file, and drag it to the Trash. Go back to the Library folder, and open the Internet Plugins folder. Drag Silverlight.plugin to the Trash, and empty.