I am in MI too. The Chicago consulate’s website didn’t clearly layout the procedure to do the process over mail ( too many nonsense questions on forms and no clear details about photos etc…and lot of contradictory chatter online about whether original passport should be sent in the mail). I took a day off on a friday and went there in person. My passport was issued in India (HYD). I filled out the forms, took my original passport and the amount of fee in the form of a money order (done at my local kroger) to the consulate by 9.30 am. If I’m not wrong, they have an open counter till around 11 or 12 in the morning. They took my passport around 10am and returned it along with the PCC at around 3PM, the same day. Be prepared to pay for parking right in the heart of Chicago’s downtown. other than that, everything was rather straightforward. My only regret is that I forgot to ask them how to do this process by mail. Hope this helps to some extent.