Loosen and remove the bolts holding the belt shields in place with a wrench. Once the bolts are removed, also remove the shield.
Relieve the spring tension on the idler pulley by removing the spring's tip with the pair of pliers on one side.
Slip the old belt off of the sheaves and pulleys. Wrap the new belt in place.
Clip the free end of the spring back onto the idler with the pliers.
Set the belt shield back in place, replace the screws and tighten them with the wrench.