I recently sold some of my stock too. I also had less than 100 shares available, and had to convert them from "A" to "B". You will need a Medallion Signature stamp on the Proper Form. I used Bank of America, but I had to run around town to find the one and only person on duty who had the stamp and authority.
The conversion form # is #2011, which you download the PDF file from Mellon's web site.
Don't sign your forms UNTIL you're in front of the person with the green Medallion Stamp. They need to witness your signature. This a safety precaution to protect your shares. I wasn't put out with the extra effort since it was for protection of my shares.
I also found the people who handle our shares at Mellon to be very helpful and nice to deal with. Give them a call if you still have any questions about filling out the form.
Also, don't waist your money on NDA UPS the forms. Use the Priority mail option. You'll notice it's a different address from the UPS shipping address, but the time involved handling your Sale is the same. A fellow coworker and I tested the system. I shipped my paper work UPS NDA, they used Priority mail. Less than a days difference in receiving our final checks. The whole process took almost two weeks, so the NDA doesn't help.