Grasp the section above the nib and unscrew the barrel by twisting it counter clockwise. Remove the spent ink cartridge. Insert a new one by inserting the cartridge into the nib section and pressing it home with the ball of your thumb until it clicks into place. Replace the barrel.
Refill an ink converter by unscrewing the barrel as described above. Twist the top of the converter in a counterclockwise direction until it is fully closed. Dip the nib into the ink bottle until the plastic section above the nib is submerged. Turn the top of the converter clockwise to raise the converter piston to the fully open position.
Remove the nib from the ink bottle. Blot, don’t wipe the nib and plastic upper section, and use a piece of absorbent tissue paper. Replace the barrel. Write a few lines to ensure that the ink is flowing freely.