Changing from Zebra G to Jowo #6

To remove the Zebra G nib unit I designed, you'll pull out the friction fit nib and feed, and then, using a 3/16" allen (hex) wrench, you'll reach into the black nib collar and unscrew the nib collar from the inside. Then, once that's removed, you can manually screw in your JoWo #6 nib unit of choice.

If it has a breather tube that extends into the body some amount, (as much as .875" with a Precession, and .375 for a Soubriquet) , you'll be able to fill it as normal, no changes. Without a breather tube, you'll have to carefully fill it much like a screw piston, where you're strategically moving the ink and the air around to get a full fill.