One way to fill your Mop is to draw up your ink and put a syringe about 2 inches down, between the nib and the container and fill it up that way. This way might take a little while. But, it does not require you to remove the nib.

The other way is,
Carefully pinch the nib and pull the nib out slowly.
You will noticed a thin middle felt strip between the wide felt strip. Make sure they stay in the same fashion when reinserting the nib. After you carefully pull out the folded folded strip, then fill your Mop with your favorite "Dye Type" ink, don't fill container all the way to the top, leave space for the nib to be reinserted along with the middle felt strip, you can add more ink by putting the ink nozzle between the nib and container or you can use a syringe.
(Do Not Use Paint Type Ink, As it Will Ruin The Felt)

This "marker/mop" is very different than any graffiti tool sold on the market today. Being it does not have a valve and the nib is loose, you have to control the ink flow. It is all in how you hold the mop that will make a differeance. you want to tag in an upright angle. Because if you tag downwards, you will get too much ink flow and make a mess. After a few tags you will get the hang of it and unserstand how it works. It is all in the wrist, I can go bombing and make the drippiest tags around and not get a drop of ink on me or my hands. That is because I am careful in regards to how I hold the mop.

You always want to store the marker in an upright angel. If you store it sideways you will make a mess. If you feel that you can't handle this mop due to the nib being too loose, you should than take the center strip and double it and put it between the big strip and reinsert the whole set up, this will make your nib tighter and you will get less drips. But, you will still have a hell of a bombing tool. I have been using these mops 25 years. So, I have alot of experieance. However, common sense should be able to make you use the mop the way it was intended:)

Carefully put the nib back into the container, it will go back in the same way it came out (use common sense when putting it in). Once it is in hold mop sideways (not upside down till you see the ink being absorbed by the felt).

What you should do is take the nib out and reinsert it a few times before adding the ink, that way you know how the nib works and you will find the best way to reinsert it...when it is time to actually fill the mop up with ink..

Now you are ready to bomb, you can control the drips based on the angel of how you hold the Mop. To refresh the nib for a drippy tag just hold it long enough till the felt is wet and bomb! Have fun and be careful!!!!!!!!!!!