Remove the old empty cartridge or the ink converter from the pen and gently push the cartridge from it’s cup like rim end into the pen, the cartridge will get punctured automatically once it is pushed in. Now invert the pen and wait for the ink to reach to the Nib point, try writing on a clean piece of paper, your pen is now ready to use.
Note : Don’t pull out the cartridge with ink in it as the ink may spill on your clothes or nearby things.