Sure, these methods are okay and all, but for my first attempt at writing an instructable allow me to propose what I find to be an easier way of getting that sweet, sweet carbon center out of the also-carbon-based-but-significantly-less-sweet wooden exterior. My proposed solution can be summed up as follows: light it on fire!
Tools and Materials
A means to start a fire (I find that a lighter works best here)
A pencil (one without paint works best, but pencils with paint also work)
A ceramic plant pot plate with a diameter around the same size as the pencil
A knife (a small, easy to handle one works best)
A cup of water (for dealing with things that are hot)
Optional: A candle slightly shorter than the plate is deep
Since you'll be lighting things on fire here, you'll also want to follow basic fire safety, such as keeping something around to extinguish any errant flames or working in a ventilated, clutter free space. As you can clearly see in the first picture, however, I am a terrible example of the latter.