Here's what I did:
You do have to change the entire controller assembly. There was the original part # and a replacement part #. I can only hope the replacement # has a better switch than the original. I am beginning to think that the Versa has the same electrical vendors that VW uses (look at the electrical reputation for the New Beetle). If they do, then our cars will continue to have electrical problems, especially as they age.
Here's a picture of the actual switch, after I removed the electrical panel from the controller (I broke 5 plastic retaining tabs doing it, see -I told you that you can't fix just the switch):
Since this controller was basically junk, I didn't care when I took it apart.