1. First unscrew the base, and you can see the 10 pen core and the metal ring in the middle.

2. Take out the metal ring, and you can see the circular gap at the ring mouth, which is the clip for refilling.

3. The nib is clamped by the clamp and directly pulled out, and the refill is taken out.

4. Insert the refill to be replaced directly from the pen tip by hand.