Step 1: Buy a refill kit. You can usually get these at drug stores or big box retailers.
Step 2: Remove the ink cartridge. There should be instructions with your printer for this . Follow them.
Step 3: Clean the cartridge. You may notice the bottom is inky. Wipe it down with a damp cloth. Just don’t press down or you may end up soaking out ink inside the cartridge.
Step 4: Put your cartridge down on a safe work area. Something flat like a table with newspaper on i is good. If you are really worried about making a mess, put a plastic bag or plastic wrap under the newspaper.
Step 5: Look for a filling hole. Some HP models have these already marked for you on the top of the case, and others do not. If your HP model has this marked you will see a small set of concentric circles. If you press lightly on the inner circle it should give way a little bit. It will be smaller than a centimeter and in the top of the cartridge. If you have one of these holes you will not need to drill. If you do not have a hole create one with a drill included in your kit. Procedure will vary based on model and kit. Follow the directions in the kit to drill.
Step 6: Prep your ink as per the instructions in your kit. This usually involves a long syringe or needle like device.
Step 7: Inset your needle into the hold you found or drilled. Use a minimum amount of pressure and begin to dispense your ink. Go slowly or you can end up with spill over.
Step 8: Once your cartridge is fill cover the hole. Most kits come with covers, but if yours does not you can use a tiny piece of duct tape.
Step 9: Put your ink cartridge into your printer and do a test print.