Product review (5 stars): Really easy replacement for issue of light not coming on when door is open
Anyone who owns a SubZero can tell you what a headache it is when something breaks.  Where I live the only "authorized" dealer charges a huge service fee to just come out and troubleshoot the issue.  They don't even offer credit if you make the repair.  So when I saw that something simple like this switch on my 690 broke, I was determined to not have to spend a fortune to fix it.  The replacement of this switch is super easy.  Just turn the power off, remove the grill cover, and the switch is right up front over the door.  There is a protective metal cover over both switches that has to be removed first.  The screw is phillips and is on the back side of the cover...kind of hard to see, but you can feel around. After the metal cover is removed, unplug the light switch leads (yellow and orange on my 690) and use a flathead screwdriver to push the tab in while pushing down on the switch with your finger.  It will pop right out. Insert the new switch until the tab clicks into place.  Replace the leads (remember to see which color went where), and you are in business.  It is really that simple.  I saved myself a ton of money and headache waiting on a repair person.  Good Luck!