You need to know the model number and the type of printer you are using before you replace the ink cartridges. Here are the steps on how to replace ink cartridge HP office jet pro 8600. First, you need to remove the empty cartridges. Then, slide the new cartridges into the empty slots carefully. Make sure you are coordinating them according to the colors marked on the printer. Now, close the lid of the printer properly. You should hear a click sound, which means everything is in place.