If you get a "damaged" error, try to download the file again, or try a different browser like Firefox to ensure the download wasn't corrupted.
A window will appear. Often, you simply drag the application icon into the Applications folder shortcut within that window. Download MAC dmg
Click the download link from your browser. Safari typically saves these to the Downloads folder, which you can access via the Dock or Finder. If you get a "damaged" error, try to
If the app won't open, go to System Settings > Privacy & Security and click "Open Anyway". If you get a "damaged" error