Remove hash browns from freezer, and thaw at room temperature for 2 hours.
In large mixing bowl, Hash Browns, Soup, Milk and Garlic, and stir well. Then add in Kielbasa pieces, and stir again.
Spray inside of 5 - 6 quart Crock Pot with non stick cooking spray.
Add potato / sausage mixture to Crock Pot and cover with lid. Cook on HIGH for 2.5 - 3 hours or on LOW for 5 - 6 hours, stirring once halfway through cook time. Note: The longer you cook the softer the hashbrowns will become, so keep an eye on it to suit your preference.
Stir one last time just before serving, and top with optional Green Onions. Enjoy!!