I am the executor for estate of a deceased individual. I must sell his house. How do I go about changing the name of the property from his name to that of "The Estate of John Doe (deceased)"?

The private house in question is located in NYC

You file for probate and that is all taken care of.
The house becomes part of the inventory of the estate, and funds from the sale go into the bank account associated with the estate.
And it must be formally appraised for the market value at the time of death.

If you are a family member and one of the heirs, you can sell the house before or after probate is final. Work that out with the court.

And normally you wouldn't convey the property to the estate. Instead, you, on behalf of the estate, will convey the property to the heir or devisee who is to receive it. Alternately, if you will be selling the property and distributing the proceeds to the heirs or devisees, you will sign that deed.

But, as Joypulv has suggested, you first have to file a probate application with the court, so as to give you actual authority as personal representative. The first thing you need to do is talk to an attorney.