just unscrew both rear axle nuts (you dont need to take them all the way off, just enough to be able to take the wheel out of the frame) remove the chain from the sprocket and chainring (just let it hang off the frame). take the wheel out completely. flip the wheel over and put it back in the frame, guiding the chain back on as you fit it into place.

or you can watch someone do it on youtube.


lol.