How do I correct an underpayment in the event that I erroneously indicated to the USPTO that I had a micro-entity status?

Use a fee transmittal (sb-17) with everything unchecked except the "Other" line at the bottom, listing the sum of the deficiencies (search, examination, issue fees) as calculated in an attached letter of "Correction of Error in Asserting Micro-Entity Status, Itemization of Deficiencies per 37 CFR 1.29(k).  Include a statement that "the error was made in good faith."