A pulverizing attachment for an excavator and a method of removably rigidly retaining teeth to one or more jaws of a pulverizer. A plurality of tooth members each have a longitudinal slot with a cross-sectional shape and a relief slot extending substantially transverse to the longitudinal slot producing a flexible end portion capable of deflection upon application of a longitudinal compression force. The tooth rails having a complimentary cross-sectional shape to the longitudinal slot slidably receive the tooth members. The complimentary shape of the longitudinal slot and tooth rail in cooperation with a longitudinal compression force applied to deflect the flexible end portions of each of the tooth members rigidly retains the tooth members on the tooth rails fixed to the pulverizer jaws.