Carefully turn the cap counterclockwise until it is beyond the retraction point and take the cap off. Remove the used refill. Take the spring on the tip of the refill off but keep it.
Insert a new refill into the barrel and put the spring back.
Put the cap back and turn it clockwise until tightened.
＊Always retract the refill when not in use.
＊Use Laban ballpoint or Parker's standard ballpoint refills.