Hi Pat,
Mayo Clinic's website walks you through the process here: http://mayocl.in/1mtmR63

On this webpage, you'll find information about:
1. Submitting an online form to request an appointment. It's quite easy.
2. If you prefer, you can call Mayo Clinic and talk with someone to guide you through.
3. Alternatively, you can ask your doctor to submit a physician referral.

Also on the page is a link to Frequently Asked Questions. Let me know if there's anything that's unclear.