If you ever need to remove pedals to ship a bike, or if you've decided to swap out your existing pedals for a different style, the process may not be quite as intuitive as you would think. Most people can do this at home if they have the right tools and know what to expect.
Preparation
You'll need a pedal wrench to remove bike pedals. A pedal wrench has a thin jaw designed to fit on narrow pedal axles, and a long handle to give good leverage. If you don't have a bicycle stand, turn the bike upside down so it's resting on the saddle and handlebars.
Pedal Threading and Removal
This is the tricky part. The pedal threading on the drivetrain side is regular, but the left pedal is opposite. This means you'll need to turn the wrench counterclockwise to loosen and remove the right pedal, and clockwise to remove the left pedal.
Installation
To install new pedals, first grease the pedal threads thoroughly. Pedals are labeled "R" for right and "L" for left. Place the right pedal into the crankarm on the drivetrain side. Carefully thread the pedal in by hand -- do not force it. Once you've tightened as much as you can by hand, finish by giving the pedal a few final turns with the pedal wrench. Once finished, repeat with the left pedal.