1. Prepare your work surface by spreading out the newspapers. Place your tools and supplies on top of the newspaper. Be sure to choose a work surface where you will have ample room. If you must work in a carpeted area, spread the newspapers over the carpet under the work surface, too.
2. Shake the black refill toner container several times. Unscrew the cap and pop open the aluminum safety seal using the screw driver. Screw on the funnel top that came with the refill toner.
3. Locate the rubber stopper on the Xerox toner cartridge. With the hopper cylinder portion of the printer ink cartridge facing up, the small rubber stopper can be found on one of the ends of the printer ink cartridge.
4. Pry the rubber stopper that covers the refill hole off of the cartridge by inserting the flat head screw between the lip of the stopper and the printer ink cartridge. Gently work the screwdriver around the stopper until it becomes loose. Put the stopper to the side.
5. Stand the cartridge on end with the refill hole facing up.
6. Insert the funnel on the refill Xerox toner container into the refill hole on the printer ink cartridge. Slowly empty the toner into the cartridge.
7. Insert the rubber stopper into the Xerox toner cartridge, making sure that it is securely in place.
8. Insert the Xerox toner cartridge back into the Xerox copier. The copier will automatically readjust the toner settings
9. Discard the newspapers carefully avoiding spilling any printer toner which may have spilled. Wash your hands immediately after working with toner powder.

Source:.ehow.com