Legal Question in Wills and Trusts in New York

I am presuing you are awaiting an acceptance of an offer to purchase assets? If this is the case, there is no requirement to sell and this is beyond an executor's unilaterial right, as he could face an exposure if some heir contested the selling price and/or terms. If one heir is acting unreasonably, perhaps the executor can have the Surrogate's Court intercede and try to move things along. Your facts are sketchy and more information may be needed to provide a better response.