There are no instructions on the web on how to do this, but it’s pretty easy.
If you have a spill in the fridge and you don’t notice it right away, there’s a good chance that you’ll get some mold build-up in the short drain tube at the left rear of the fridge compartment. There’s a condensation collection trough back there that will fill up with water and leak out. You’ll notice water leaking out of the front of the fridge, and there’s a good chance the door will get really sticky and become hard to open. You can get to the trough by removing the bottom drawer. Just pull the drawer out, then gently pull up on it till it pops free, then slide it out. The trough is probably full of water… If it is, here’s how to fix it.
Remove the kick plate from under the fridge by unscrewing the two #2 Phillips screws and pulling the kick plate off. Look under there and you’ll find a drain pan. Then pull the drain pan out by pushing up on it a bit, enough to get the feet to disengage, and pull it out. Give it a good scrub and set it aside.
Take a gander at the back right of where the drain pan was located. You’ll probably see some mold hanging down off the drain tube. Reach your hand back there and pull off the mold. If that clears the tube, water in the trough at the bottom rear of the fridge will start draining out the tube.
If water does not drain out, stick a short stick up the tube to clear it. I used a golf tee to do it. That cleared the plug and the water flowed out.
To prevent a recurrence, pour a cup of bleach into the trough at the bottom rear of the fridge, after replacing the drain pan.
Hope that helps everyone and avoids a costly service call.