How do you correct a situation when the contributions W/H for one of the FSA accounts exceed the Annual Election Amount and W-2 have already been issued?

Fix everything so that it's the way that it should have been:

* Refund the excess withholding
* Correct any related tax withholding and make the necessary adjustments/corrections on the employment tax forms
* Issue a corrected W-2 to match the annual election amount and the corrected withholding