Originally this was just supposed to be a quick once-over-the-stencil with the spray can while the dog played in the yard, but turned into a full-repaint (which the bike needed anyway).
The technique here is *far* from looking "nice", but for the "rattle can black" aesthetic that I think fits this bike, it's perfect.
(If you really want a nice, shiny looking paintjob, you should absolutely sand down the old paint first, prime the frame, wetsand between coats, and then apply a clear coat.
Panda Face has an instructable for that here: http://www.instructables.com/id/Bike-Painting-Tips/)
Here are some things you'll want for this:
1: Paint (obviously)
2: Metric Allen Wrenches
3: Big-Huge crescent wrench
4: Lots of painters tape
5: 15mm box wrench
Step 1: Take off the wheels and the seat
Turn the bike upside down and let it rest on the handlebars and the seat.
The front wheel is a "quick release" and can be taken off with finger tools, the rear wheel requires a 15mm box wrench (or socket).
To get the front wheel off, actuate the quick release lever, loosen it a few turns, and the wheel should just lift out of the fork. (If this bike has wide tires, you might have to also disconnect the brake. To do that, manually pinch the brake together with your hand, and lift the cable out of the retainer on the brake. When you do this, the brake will be allowed to fully open, freeing the wheel).
To get the rear wheel off, you'll need to loosen the 15mm nut on both sides. The wheel should then lift out. My bike doesn't have a rear brake, but if yours does, use the same procedure from the front brake. If it has a *coaster* brake (meaning you pedal backwards to stop), you'll also have to remove a 4-5cm long "brake arm", which is attached to the frame.
For the seat, there is a bolt that you'll loosen near the back of the seatpost, which will free it. Just loosen the bolt, and pull the seat out. Your seat may also be fitted with a quick-release. In which case, just actuate the lever, loosen it a couple of turns, and pull the seat out. If the seatpost is stubborn, rotate it in the tube a few times, which should loosen it up.