1. Enlarge the vent hole on the top of the cartridge using a small drill or knife.  (Do not remove the top.)

2. Fill with 10cc of ink, insert the needle into the vent hole and push down into the center of the cartridge. Slowly inject up to 10cc of black ink into the cartridge.  

3. Set above a paper towel for half an hour as a drip precaution. Expect a few drips. Do not allow the cartridge to touch the paper towel at this point, since the towel will draw out the ink.

4. Replace the cartridge and run 1 - 3 cleaning cycles as per printer instructions.

If necessary leave cartridge in printer for up to 24 hours. (Allows ink to flow to the print head).

Empty cartridges should be refilled immediately.
Also this work is done best over the sink.