Turn the bicycle upside down so it rests on the seat and handlebars. Reach down to the brake and grip it so the cable fid--the metal and rubber gasket at the end of the cable--releases off the brake cradle. Let the brakes pop open.
Grip the quick-release lever--the metal lever in the center of the wheel--and push it so it is perpendicular to the bicycle. Turn it counter-clockwise until you feel the release loosen and the wheel has slack off the frame wheel fork.
Grip the wheel and pull up, bringing the axle out of the frame's fork. Push the brakes farther apart to make room for the wide tire as you remove the wheel from the bicycle.