Mechanical pencils allow precise, thin writing without the need for constant sharpening. The process of refilling the pencil is as easy as writing with it. With the purchase of a lead refill bottle, you can write for months. The Pentel E-Sharp mechanical pencil is available in two lead sizes as of 2011.
Purchase a bottle of 0.5mm or 0.7mm replacement lead, depending on the pen model, at an office supplies store or online. You can usually buy about 20 pencil leads at a time; your pencil will only hold about five or six, so you will have plenty of extra lead for more refilling.
Remove the white eraser at the top of the E-Sharp pencil, and set it to the side. Lay the pencil on its side horizontally so as not to let any lead escape the pencil.
Grab four or five pieces of replacement lead with your index finger and thumb, and slide them into the hole where your eraser was placed. The lead will fall into the inside of your pencil, where it will be stored until you press the pencil eraser down, allowing more lead to enter the tip of the pencil.
Replace the eraser, and press the eraser down until the tip of a lead piece comes out of the pencil. You are now ready to start writing.