To attach the mop, first, screw on an L-bracket on each side, four holes from the wheel axle. Screw on the servo motor to an X-bracket with the L-bracket between the X-bracket and the motor. On the opposite L-bracket, screw on a black axle support. Then, take the mop and trim the ends down with a knife so that the unit fits within the width of the frame. Slightly bend the mop's two tabs towards each other; this will hold it so that it moves with the axle. Next, take a 12 inch axle and slide it through the L-bracket, through the mop's tabs and into the motor. Use a stop-collar to hold the axle in place. You may need to use hot glue to ensure that the mop moves with the axle.