The mower deck on your riding lawn mower houses the blades that cut the grass. On top of the mower deck is a series of pulleys and belts, driven by the mower's engine, that spin the blades for cutting. After a few seasons use, the belts on the mower deck can wear down, eventually cracking and breaking. Replacing belts when they become stretched or show cracks can prevent damage to the underside of the machine and ensures your blades are moving properly. To replace the belts on some mowers, the mower deck requires removal.
Roll your mower onto a flat, paved surface and engage the parking brake. Remove the spark plug wire from the spark plug to prevent the mower from starting while you're working underneath the machine. Take the keys from the mower's ignition.
Clean all loose grass from the mower deck and lower the deck to its lowest position.
Pull out on the deck lock levers on each side of the tractor, located toward the back of the deck behind the mower belts. The placement of deck lock mechanism might differ from mower to mower.
Move the deck slightly forward and lift up on the rod that holds the mower deck in place. The deck will come loose and roll out from under the mower.