HP OFFICEJET 4500 - Manual (Page 215)

3. Wait until the print carriage is idle and silent, and then lightly press down on the ink cartridge to
release it.
4. Pull the ink cartridge toward you, out of its slot.
CAUTION: Do not touch the copper-colored contacts or ink nozzles. Doing so can result
in clogs, ink failure, and bad electrical connections.
5. Hold the ink cartridge with the HP logo on top, and reinsert the ink cartridge. Make sure you
push the ink cartridge in firmly until it snaps into place.
6. Close the front access door and check if the error message has gone away.
If the problem persists, try the next solution.
Cartridge Problem 211