Grasp the grease marker firmly in one hand. With the other hand, take hold of the short piece of string sticking out at the writing end of the pencil.
Slowly pull the string down towards the blunt end of the grease pencil. Pull the string only a short distance. As you pull, the outer colored wrapper will split, revealing an inner paper core.
Slowly unwind the paper core, which is perforated. Tear it off close to the body of the pencil so the paper does not get in the way when you use the pencil or get caught on anything.
The string will get longer as more of the pencil is unwound. If it is too long and gets in the way, cut it with a pair of scissors or knife. Do not rip the string off of the pencil.
Use a pen knife to sharpen the point on the grease pencil, if a thinner point is desired. Alternatively, a crayon sharpener may be used.