Ultimately I had to replace the fan. I initially thought the problem was that the blade was out of balance, but the shaft on the motor had come loose and had to be replaced with another purchase. This was no fault of the purchase I made and I went ahead and used the new fan blade. Now the refrigerator is working very well.
The videos were a definite help, as well as the prices being cheaper than anywhere else I saw. Delivery was VERY fast, as it came the next day on a two day shipping order.
I will definitely use AppliancePartsPro.com the next time I need to repair an appliance, which will probably be soon given the age of my house.
One last point: the biggest problem I had was diagnosing the problem. Eventually I figured it out reading the Q/A online for some of the parts.