You will need to have
DVC review any offer before it can be sold. DVC will have the opportunity to purchase the contract for the same offer. I'd sure provide the offer to DVC for ROFR before accepting any payment from your friends.
You cannot "sell" it to anyone without first passing ROFR- either thru Disney's approval of the contract or from Disney's lack of comment after 30 days.
Yes, you are thinking too simply when you say, "can't they just send us the money, we pay off the mortgage and then change the title??" If you approach it in that fashion, Disney could still take the contract and you'd have to repay your friends the money they paid you. The closing cannot be completed until Disney has either signed off on ROFR or allowed the 30 day period to expire without comment.
Remember that Disney does hold all of the cards and if proper procedure is not followed the "new " owners won't be able to make reservations thru DVC. Disney does have the final word on these sales.
You do not need a broker to sell your contract, but you do need to follow the procedure spelled out in the contract.
I'd submit any offer made by your friends (before accepting any payment from them) and see what DVC says. In a worst case scenario, DVC would purchase your contract at the same price and you'd get the same amount already agreed to with them.
Good luck!
