If using a Windows mobile device or tablet, press and hold on the icon you want changed.  ” A list of all available Windows icons will display on-screen. Alternately, click on “Browse” to select an icon from your personal collection. Icons from your personal collection must end in the .ico extension. Use a free online file converter such as Convertico.com or ICOConverter.com to convert an image or photo into .ico format. The app icon will now be changed to the icon you selected.

Summary:
Right-click on the app icon you want changed on your Windows PC. Select “Properties,” then click on the “Shortcut” tab in the Properties window. Click on “Change Icon. Select the new icon you want to use from the list of options provided. Click on “OK,” then click “OK” again to confirm the change.