I'm not sure that you're going to get much specific help on this issue since I gather that most people on this board are current
DVC owners or prospective buyers. There may be a few owners out there that have resold one of their multiple DVC contracts.
I can give you a few tips based on my investigations prior to my recent resale purchase. I found 4 primary resale brokerages that specialize in DVC (links included below). I believe some of them have seller information listed right on their websites, but you ought to give each of them a call to find out what their commission rates would be for your unit. Typically the buyer will pay all closing costs (approximately $500), but the seller will pick up the broker commission and the DVC transfer fee ($100).
From following the listings for many weeks, I can tell you that you'll struggle to sell your property quickly if you have "borrowed" points from next year, and, to a lesser extent, if you have used most of the current year use points. You can drop the price to compensate for this, but at a certain floor, DVC will exercise their ROFR. That fact seems to scare away buyers as I've seen many properties with low points and costs remain available for as long as I've been reviewing the listings.
If you use a broker, they will handle all of the paperwork for you and guide you through the resale process. It is certainly possible to complete a transaction directly with a buyer (and I believe there is a timeshare bulletin board on the internet that tries to match buyers and sellers), but you'll still need to enlist the services of a closing service for the title transfer.
Best of luck to you in obtaining a quick and successful transaction.
http://www.dvc-resales.com/
http://www.dvcbyresale.com/
http://www.reid4florida.com/disney_hot_buys.htm
http://www.atimeshare.com/disney/