The second version of the Modern Fuel mechanical pencil is up on Kickstarter ... and 0.9mm lead sizes for any of your drawing needs. The pencil comes with an Allen wrench for when you need to ...

You might have, or can inexpensively buy, a mechanical pencil which has the feeder button on the side rather than on top, as usual. With the pencil in hand, [ptkrf] shows you the simple procedure ...