Mark, I take if from your question that you are the 'seller' trying to terminate an agreement that has a buyer contingency stating that the buyer needs to 'sell their property' prior to buying your property. If this is the question, and you are using a Realtor, it is a matter of contacting the Realtor and have them take care of these details and amendments for you. If you are doing this on your own , without a Realtor, I suggest that you contact your attorney as I'm not familiar with your state laws governing this issue. Hope this helps. Gail