Thanks to both of you. Here is my current status:
Tesserax, I had gone through those steps but I was not getting an Update button. Still am not seeing one.
Joseph Kriz, I went through the steps you gave me, and did not get an update button. When I went to About Airport Utility it says I have version 6.3.1, not 6.3.2, but I am not seeing a way to update.
When I click on the airport icon in the Airport utility I get a dialog box that says, "This version of Airport Utility requires this Airport Extreme use firmware 7.3.1 or later. Use Airport Utility 5.6 to update this base station. Airport Utility 5.6 is available at Airport Service and Support."
But when I go to Airport Service and Support I am not able to update anything. I go to the same place that Tesseract shows in his last post and there is no Update button.
So, I am stuck... Ideas?? I appreciate your help.