Melanie, a lot of the girls on the forum did all their paper work at home went to the courts and signed their papers, in this you dont have to exchenge vows or rings but this way you will know that your marriage is legal 4 sure if you're worried. This way you can just have your Ceremony in Mexico
as for Mexico...
Maybe the other girls that already got married in Mexico canhelp u out a little more but this is what i was able to find
Documentation required for each participant in a Civil Marriage Ceremony in Mexico (we recommend that you bring at least one complete set of copies, plus the originals):
Valid Passport.
One additional form of valid picture identification (normally a drivers license)
Original birth certificate.*
Mexican entry visa or tourist card (provided by Customs upon arrival at the Cancun International Air port)
Blood tests results, specifically for blood type, H.I.V. and S.T.D. These tests and the required medical certificate are normally taken care of at the hotel with results in 24 hours.
If either party has been married before, the proper dissolution documents, dated at least one year prior to your Mexico wedding date, must be provided:
a. If by divorce, a certified copy of the divorce decree(s)*
b. If by death, a certified copy of the death certificate(s)*
Legal documentation of adoption or name change, if applicable*
Two witnesses for the bride and two witnesses for the groom (Four witnesses total). If the witnesses are not Mexican citizens, they must provide their Mexico entry visa or tourist card, passport and another form of picture identification. If witnesses are not available, they can be supplied as part of your package.
Completed and signed “Application for Civil Marriage”. This is normally ready for you both to sign at our initial consultation meeting upon your arrival in Cancun.