How To Replace the Ejector Gear
There are two types of ice makers, those in which all of the parts can be individually replaced and those in which some of the parts are clustered together into a control module. To determine which model you have remove the outer face plate. If there is knob, pull it off first, then pry off the face plate with a small screwdriver.
Before replacing the ejector gear, unplug the freezer to avoid an electrical shock hazard.
Modular units have holes in the module's face plate for test probes. If you see several holes, each marked with a letter, it is a modular unit. The gears are enclosed and the entire module must be replaced. Click on this link for instructions on replacing the control module.
Component units, like the one shown below, can be identified by their exposed gears and lack of holes for test probes.
There are two exposed gears which mesh together. If either of the gears are worn, then they may fail to turn the ejector cam which ultimately pushes the ice out from the ice mold.
Determine which gear needs to be replaced (it may be worthwhile to replace both now). Inspect how the gear is held in place. Some gears use retainer clips while others simply slip over the shaft. Remove the clip using a small screwdriver or needle nose pliers and then pry the gear up and off of the shaft.
To install the new gear, align it with the flat spot on the shaft (if any) and with the other gear and firmly press it into place. It may be helpful to use a tool such as small diameter socket to press the gear down over the shaft.
Replace the cover plate and knob (if any), move the shutoff arm down into the "on" position, plug in the freezer and test the ice maker.