Unplug machine and tip it back. Remove the belts, turn the transmission pulley counterclockwise. Have someone watch the agitator. The agitator should move back & forth. Turn the pulley clockwise & it will release the brake and the tub will spin. If you can not get the agitator to move the upper bearing in the transmission has seized,most likely from a seal slowly letting water down on top of the transmission. There used to be a kit that was reasonable to replace the transmission. Now everything is sold separately and more expensive.