Hold the ink pen with one hand and the pliers with the other hand.
Grip the piece of plastic holding the tip of metal part of the pen against the casing with the pliers and pull until it pops off. Often the casing on these types of pens is white or clear and the plastic that holds the tip of the pen is black.
Remove the metal part of the pen and the ink tube by pulling them from the casing with your fingers.
Squeeze the bottom of the pen gently with the pliers until the plastic cap at the end of the casing pops out. You may need to pry it off with your fingernails.
Replace the plastic piece that held the metal part of the ink pen by snapping it back into place with your fingers.
Wash the pen using dish soap to remove any ink residue. To do this, squirt a drop of dish soap and a few drops of warm water into the casing, cover both ends of the casing with your fingers and shake the casing. Rinse with warm water. The pen is now ready for blow art. Drizzle food coloring into the casing and blow into the wide side of the pen.