How do I refill the ink tanks on the HP DeskJet GT 5820?

Lift the ink tank lid, remove the cap of the tank you want to refill, then prepare the ink bottle by removing its cap, removing the seal, reinstalling the cap, and pulling open the top part of the cap. Hold the ink bottle on the tank nozzle and fill only to the maximum line — do not squeeze the bottle during this process. Close the ink tank cap securely and close the ink tank lid when finished. (Page 58-59)