Park the John Deere LA100 riding lawn mower on a dry level surface. Lower the mower deck fully. Set the parking brake, and pull the key out of the ignition.
Place a floor jack under the front frame of the mower. Jack the mower up and slide two jack stands under the frame, one on each side of the jack. Lower the jack just enough so that the jack stands support the weight of the mower.
Find the grease fitting for the front wheels on the inside wheel hub. The grease fitting is on the side of the hub. Locate the spindle grease fitting where the axle meets the mower frame. The fitting points to the front of the unit. There is also one grease fitting on the center of the main front axle, pointing to the front of the unit.
Raise the jack just enough to move the jack stands. Once you remove the jack stands, lower the mower completely.
Remove the screws securing the mower spindle cover on the top left of the mower deck with a socket wrench. Pull out any dried grass clippings from under the spindles.
Find the grease fittings at each spindle. Depending on the size deck you own, the fittings are either at the base of the spindles or on the side of each spindle.