Put on protective work gloves.
Set the mower on a flat, level surface. A driveway or a deck usually work nicely.
Identify the height adjustment lever on each of the mower's wheels. Typically, the lever is located on the side of the mower deck between the deck and the wheels.
Identify the levels that control the powered wheels. If you aren't sure whether the front or rear wheels propel the mower, start the mower and gently tilt the mower back so that it only sits on the rear wheels. Engage the drive mechanism. If the mower moves forward, it is a rear-wheel unit. If the front wheels spin, it is a front-drive unit.
Turn off the mower. Pull the adjustment lever of the power wheels toward their respective wheel and slid the lever down toward the ground. Allow the lever to retract once it is in the lowest position. This will lock the wheels in the lowest position possible.