Hello,
I've done this twice now. The first time was Pearl harbor day, Dec 7, 2003, and the second was May 27, 2004. It is a fantastic ceremony. On both occasions, I inquired at City hall for available dates during my stay. There was opening available each time, and I got to choose which date. It helps to take long trips, as there are often more available dates a week or so out. They take your name, hometown, and branch of service at that time. On the day you are given, you are told to be at the flagpole area around 4:40pm, and look for the security CM's. When you arrive, they do a brief run through of the ceremony, and tell you where to stand, and what to do. It's actually pretty simple. At 5:00pm, the band comes out, sometimes the full band, sometimes just a small group. They make an announcement to the crowd with your name ( or the vets), hometown, and branch of service, do the flag lowering ceremony accompanied by the band, and then you ( or the veteran) marches off towards Expo Hall with the flag after it's folded. They then present you with a very nice certificate with your name printed on it ( I don't know if they do this for same day volunteers), a very nice Veteran of the Day pin, a Mickey USO large pin, and a coupon for a free picture of your participation in the ceremony. You get the picture inside Expo Hall. It's very nicely done, and always draws a great reaction from the crowd. I plan on trying for it again on my upcoming trip, keep an eye peeled for the TR!!!
Hope that helps,
Take care,
Bill