Step One:

This image is the endcap, which consists of the endcap itself, the lead sleeve (where the lead comes out) and the lead.

Step Two:

This bulk of the mechanical pencil, here you are shown the body of the pencil, the lead size, the chuck & chuck ring, spring, lead tube reservoir and the push button, which is comprised of the push button, the eraser and the pocket clip.

The lead tube reservoir is where the extra lead is stored and the spring, the chuck & chuck ring are all involved in the advancement of the lead. When you push down on the push button, the spring compresses and forces the lead to move through the chuck & chuck ring until it passes through the lead sleeve and out the endcap.

Step Three:

WARNING: Do not pull out on the push button, doing so will cause the pencil to come apart, spilling the spring, chuch & chuck ring to the table, renedering the pencil useless, unless you want to take the time to put it back together. If you do happen to do this, I suggest just removing the rest of the lead and discarding the pencil.

Step Four:

To write with this mechanical pencil, you should push the push button as many times as it takes to get the lead to the desired length and then apply the lead to the paper. Once the lead and paper are in contact, you can either write or draw but if you are doing it properly, there should be some markings on the paper.

Do not advance the lead too far out, doing so will cause the lead to break when pressure is applied. If this does happen, advance the lead and try again.

Step Five:

To erase with this mechanical pencil, apply the eraser to the paper and move it across the markings you want to remove. The motion you use to erase does not matter, you should see the markings disappear as you erase.

Step Six:

To add new lead to the pencil, simply remove the eraser and feed the new lead through the opening in the end of the push button. Removing the eraser will give you access to the lead tube reservoir, the place where the lead is stored. Once you have installed new lead, replace the eraser, advance lead and continue.

As a reminder, this pencil takes 0.7mm lead, which is fairly common and can be found at a large number of retailers.