Let's be clear, while it may be a shocker to some of us, Disney does not make laws. The ROFR provisions of the DVC contracts indicates the full terms of the deal should be included and thus if there are terms directly connected to the sale they should be included in ROFR. Failing to do this is not breaking the law, it's breaking the terms of the contract which could give DVC grounds to invalidate the contract.
How about offering your friends a very generous commission or finders fees for finding the buyer of the contract? The benefit is that then if DVC exercises, they still have to pay the commission.
I would personally reach out to one of the reputable closing companies talked about at length on this board. They handle the full process OTHER THAN the sales contract. The folks at the DVC Store who posted above are also well known and if they offer a cost effective option just to document, that also seems like a reasonable approach. While it's not impossible to do alone, someone will have to deal with all the deed filing formalities which are quite pedantic.