Once you have accepted an offer, you (as the seller) will need to submit the offer to DVC for the ROFR process. They have 30 days to consider ROFR. They may accept the sale at the terms of the offer, decline purchasing the resale or make no comment at all.
You do not need to contact them in advance, but that might be wise so you have aan understanding specifically what they will require and where to send it.
I second the suggestion to contact The Timeshare Store. They were wonderful when we sold our SSR contract and made everything painless. They help you price the contract to sell and make any and all suggestions you need. Ours sold within a day or 2 of getting listed.
As long as you don't overprice the contract, yours should sell just as fast.