The blade assembly in Waring Pro blenders -- food and beverage, specialty and bar blenders -- attaches to the base of the blender jar. The assembly may attach to the unit with a plastic collar or may have a "permanent" design. Depending on your model, this means that you will need to replace the assembly only or the entire glass jar. Waring offers replacement parts online and over the phone. The method you use to procure and replace the required part(s) depends entirely on whether you know the part number.