Drill a hole where the red arrow indicates in the next photo.
Preparation:
Fill the syringe with 5 cc of back ink using a needle to collect the ink
For the drilled hole - as shown in first photo, - put the needle to the bottomand inject the ink slowly, gradually removing the needle out.This is to better spread the ink in the sponge interior.
When ink appears at the hole, the cartridge is complete.
Dry and cover the hole with adhesive tape.
Rest:
It is best to rest the cartridge 10 minutes with head down.
Do not rest on an absorbent paper.
This is done in order to distribute the ink evenly over the sponge(Allows ink to flow to the print head).