Step 1) Put the cartridge on some paper towels in an area where you can tolerate a spill. Turn the cartridge on its side with the top facing you and the ink reservoir now on the bottom. The printhead is now at the top rear.
Step 2) Bend the last 1/4 inch of the end of the syringe needle to a 45 degree angle. Fill the syringe roughly with15 ml of ink.
Step 3) You should see two vent holes on the lower half of the cartridge. They are probably under the label. Locate the second vent hole from the bottom. Insert the needle here.
Step 4) Angle the needle toward the back wall where the reservoir and the foam area intersect. Rotate the needle so that the needle is bent downward. There is an small channel here that you are trying to reach. If the needle cannot reach it, be sure to get under the foam.
Step 5) Very S-L-O-W-L-Y inject the ink so that it flows into the ink tank.
Step 6) On most of these cartridges you can see the reservoir fill.
Step 7) Tape over all vent holes and air channels with electrical tape to prevent leaking during storage and transportation. Remove the tape just before you print.
Step 8) Set on a paper towel for an hour as a drip precaution. Expect a few drips -- they are necessary to allow the printhead to get ink.