I don't see "Change My Deduction" button/link. I followed the instructions in the "How do I change from the standard deduction to itemized (or vice-versa)?" help topic

Go to the Deductions and Credits section of your return.  Scroll to the bottom and click the button Done with Deductions.

There will be a few screens that come up showing various information, but keep moving forward and then you will see the one that tells you which deduction you are taking, Standard or Itemized.  There will be a check-box on that screen that can be used to change your deduction to the other method, along with a comparison of the two choices so that you know which one is larger.