Turn off the engine and engage the parking brake. Set the PTO/Blade engage knob to the "Off" position.
Lower the cutting deck by moving down the deck lift lever all the way.
Remove the PTO belt. The PTO belt is threaded around the PTO clutch, which can be found near the front of the cutting deck.
Rotate the deck support pin to the right and pull it out. The deck support pin can be found on the left-hand side of the cutting deck.
Rotate the second deck support pin to the right and pull it out. The second deck support pin can be found on the right-hand side of the cutting deck.
Pull the deck lift lever up all the way. Slide the cutting deck forward, and then to the right. Pull it out from underneath the tractor.
Disconnect the black wire from the battery terminal, and then disconnect the red wire. Remove the battery and the battery tray.
Grab the drive belt with both hands, one hand on each side of the idler pulley. Pull the belt gently towards the left side of the tractor until it disengages from the idler pulley.
Move the double-idler bracket forward slightly. Unhook the idler extension spring, which is attached to the double-idler bracket.
Pull the drive belt off of the idler pulley and the double-idler bracket.
Unplug the cable assembly from the electric PTO clutch. Unscrew the hex bolt in the middle of the PTO clutch. Remove the PTO clutch.
Lower the engine pulley. The engine pulley can be found at the front of the tractor. Remove the old drive belt by feeding it from the front to the back of the cutting deck.
Threaded the new belt through the cutting deck, in the exact same pattern that the old belt was threaded.
Replace the PTO clutch and tighten the hex bolt using your impact wrench. Use between 38 and 50 foot-pounds of pressure. Reattach the idler extension spring. Plug the cable assembly back into the PTO clutch. Reconnect and replace the battery and the battery tray, being careful to attach the red wire first and the black wire second. Replace the cutting deck by reversing the directions for removing it.