1. Turn off the mower and disconnect the spark plug wire.
2. Tip the mower on its side.
3. Remove the lower blade guard by taking removing the bolt.
4. Locate the drive belt pulley on the bottom of the mower deck.
5. Place the replacement belt over the crankshaft at one end and then route it between the idler arm. Wrap it round the main drive pulley of the engine ensuring correct alignment in the pulleys' grooves.
6. Reattach the belt cover.
7. Tip the mower upright.
8. Reconnect the spark plug wire.
Note: Be sure to refer to the owner's manual or consult a qualified technician if you have any doubts or difficulties during the repair process.