Assuming you are referring to manually pushing the John Deere Z225 lawnmower, there are a few things you need to do. First, make sure the mower is in neutral. Second, locate the push bar at the rear of the mower deck. Third, with your foot on the brake pedal, grasp the push bar and slowly walk backwards while pushing down on the bar. The mower should start moving forward. If it doesn't, check to make sure nothing is blocking the wheels or preventing them from turning freely.