Step 3: Take out the front forks
Beneath the nut is a washer, and below that is something called a "race". It rotates against the top set of ball bearings. The race should just come off with your hands, but if it doesn't you can use a rag for extra grip. If /that/ doesn't work, you might need to get a vice grips or wide-mouthed-pliars. Really, though, as you'll see during re-assembly, this shouldn't be tight.
Once these three things are removed (nut, washer, and race), the fork will fall out of the frame. At the top and bottom of the tube that it fits in are some cups, and in those are some bearings. Do not lose the bearings.