Move the John Deere LX188 to a flat, level surface. Place wheel chocks behind the rear wheels and set the brake.
Raise the front of the mower, using a jack. Place jacks stands under each side of the mower frame at the front. Lower the jack so the mower is resting on the jack stands.
Remove the cap from the wheel hubs using a flat-tip screwdriver. Remove the snap-ring from the shaft using snap-ring pliers on each wheel. Remove the wheels from the front of the mower.
Place the new wheels on the front of the mower. Install the snap-rings on each side of the shaft using the snap-ring pliers. Place the cap on the wheel shaft on each side of the mower and push firmly until it snaps into place.
Raise the mower using the jack and remove the jack stands from under the frame. Lower the mower to the ground.