Disconnect the spark plug wire from the top of the engine, and ground it to the engine by laying it over it or bending it so it stays touching the engine.
Open the belt cover assembly by removing hardware and lifting it off of the engine. Use caution when lifting the cover to avoid bending or kinking the clutch cable.
Remove the old belt by stretching it enough to pull it over the edge of the smaller pulley on the end of the engine then feeding it through and over the other pulleys.
Install the new belt by weaving it through the pulleys in the same manner the old one was. Stretch the new belt slightly and gently pry it over the smaller pulley on the end to finish installation.
Place the belt cover back over the belt assembly, and reattach any hardware you removed.