To replace the ink in your HP DeskJet 3755, turn on the printer and open the front cover to access the ink cartridge area. Await the carriage's arrival to the center. Pull out the cartridge you wish to replace by gently pressing down on it. Unpack the new cartridge, remove the protective tape, and insert it into the correct slot—black on the right, tri-color on the left. It will click... https://www.pinterest.com/pin/972918325748610394