It is similar to doing a real estate closing. The listed owners need to transfer their interest to a new deed that has the currently listed owners on it plus the one you want to add. Note if you have an existing mortgage on the timeshare, you will not be able to do it without paying off the mortgage. You have to pay any taxes and fees to the government entities required by the transfer and recording of the deed and you need Disney to sign off on its right of first refusal (which it will automatically do unless this is a sale). I believe MS (accounting or records) can actually provide you some info on how to do it including forms, and title and closing companies also provide the service for a fee. Total cost should not be much but there are costs.