How to Insert Ink Cartridge:
Step 1: Disassemble the Pen: Pull out the ink refill converter, then you can see a protrusion in the grip section, this part is what punctures the cartridge and carries ink to the tip.
Step 2: Insert the Opening into the Grip Section: Insert the cup-like rim end into the grip section.
Step 3: Press Firmly: Push the cartridge in firmly until you feel the cartridge puncture. This may take more force than you expect.
Step 4: Leave the Pen Tip Down: Wait until ink saturates the feed.