First, call your employer(s) from that year and request reprinted W-2 forms, because you've moved three times since then and have long since lost anything and everything of such importance. Provided they even remember who you are and believe that you're a former employee, wait two to three weeks for them to be mailed, because despite your most specific instructions, they will be sent to the incorrect address.

Next, lament the fact that you can no longer find your original tax return for the year in question, although you can quickly find them for years previous and since. Try not to kill something when you realize that you've got to fill out that year's return again to get the correct data for the amendment form.

Contact either the Internal Revenue Service or your State Department of Revenue, and upon speaking to an actual human being, suck up enough dignity to admit that you seem to have filed the incorrect return for the year in question, and that you do not, in fact, owe them $600 in back taxes. Try not to lose heart when you are laughed at. Remember, these people own your ass.

Make an appointment with everyone you know, so that they will all stop by your office while you're trying to fill all of these forms out. It helps if you work at an accounting firm, so that being up to your eyes in tax forms is really nothing unusual. This also makes access to tax forms from years past much easier to find. In fact, I highly recommend finding employment at a CPA firm, just in case.

Call the IRS or State DOR three more times, trying to track down your own personal caseworker whose name you can neither spell nor pronounce, to find the address the return needs to go to.

Finally, be sure you send your things certified mail, so that you'll know when it's gotten there, realizing that if you'd done this the first time, you wouldn't be in this pickle.

Sob quietly under your desk.