Just give MR a call. They will fax you a form that you will need to fill out and sign one part. You will then need to have your spouse fill out and sign the other part. Once you have it completely filled out and signed by both of you, fax it back to Marriott.

And yes, if I remember correctly, you are correct in that the amount transferred will be in a 1000 increment (i.e. 2000 points probably in your case) and the amount will be just enough for you to order whatever award you need. (Note that you will need to order the award as part of the process as well.)