Fortunately for you, you can expunge DUI in South Dakota (unlike many other states, which do not allow DUI expungement). You can only do so if the DUI was a misdemeanor (the less serious category of crime) and not a felony (the more serious category); if this was your first or second DUI, it should have been treated as a misdemeanor and you should be expungement eligible; you can check whether you are by reviewing your conviction. If you are eligible for expungement, hire an attorney to help you: there's a lot of paperwork, you need to submit to a chemical dependency evaluation, and you should submit character references, too. A lawyer experienced with expungement will greatly increase your chance of success.