How to Refill Ink Cartridges on an HP OfficeJet 6500

1. Place your spent cartridge on a stack of paper towels. Choose a work area where you can tolerate an ink spill.
2. Place the cartridge in an upside down position so its outlet port faces up.
3. Fill a syringe with 4 ml of the correct color ink.
4. Insert the syringe’s needle into the cartridge’s outlet port, and insert just a drop or two of ink onto the felt pad inside the port. While inserting the needle, don’t go in too far, or you will damage the felt pad. The felt pad should quickly absorb the ink. Keep going until the pad stops soaking up the ink. Another clue to stop is when the ink starts bubbling out of the vent hole, which is located on the opposite side of the outlet port.
5. Dab a towel onto the felt pad. This will soak up excess ink that couldn’t be absorbed by the cartridge.
6. Repeat process for other spent cartridges.
7. Place the cartridges back inside the printer and run a few cleaning cycles.