Unscrew the main compartment of the pen, detaching the barrel from the point of the pen. This will show you that there is a plastic tubing inside the pen, which is used to hold the ink. You will want to make sure not to touch any visible ink that might be exposed, as this could make the ink get onto your clothing or skin, which can stain.
Insert the opened end of the tube, which has a reservoir on the opposite end, into the bottle of ink. Since the tube acts like a capillary, it will draw the ink inside the tube and into the reservoir. Once the reservoir is full, carefully put the pen compartments back and screw them together tightly.
Continue to use your Parker fountain pen. If you notice excessive ink leaking out or if your pen is not disbursing ink at all, then you may not have filled your Parker fountain pen properly. Keep a towel next to you the first time you try your pen in case it has a leak. Once your pen is filled properly and is in working order, you can begin using and enjoying your Parker fountain pen.