I need to check my defrost timer to see if it needs replacing. I removed the plastic lens cover at the top of my refrigerator, but can't locate the timer dial. (According to an old post about this model, "The defrost timer is located in the roof panel of the fresh food compartment,You can remove the clear plastic light lens cover and access the defrost timer notched timer dial and advance it to any part of the cycle you wish."). Is there a way to access the defrost timer dial without removing any further parts? Also, when I do locate it, how do I advance it?

Thanks for your help.