Thank you for the information and your question. Although you are entitled to file a petition with the Naval Discharge Review Board, there is no automatic upgrade of OTH discharges. There is information that goes around that there is an opportunity for automatic upgrades after a set period of time. That, is an urban legend and is not true.
Therefore, you will have to have evidence to prove to the Board that your discharge characterization was issued in "error" or was a clear "injustice."
If you could convince them somehow that your urinalysis was faulty, that could result in an upgrade. However, the onus is on you. I might suggest, because they understand the legal arguments and precedents better, that you consider hiring a military law firm to assist you with your petition. There are many civilian lawyers who have military law practices that handle post-service issues like this. You can simply do a search online or contact your State's Bar Association Lawyer Referral Service.
If you would like to read up on the process and see the form, etc., you can find the Board's website at: http://www.secnav.navy.mil/mra/CORB/pages/ndrb/default.aspx
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