How is land that the deceased sold before his death and received its price, to be vacated, given the presence of minors and the fact that the power of attorney granted to the seller became void upon its grantor's death?

If the father sold the land and received its price before his death, then neither the minors nor anyone else has any connection to it. It belongs to the buyer, and it must be vacated for him and he must be enabled to take possession of it. The agency for selling the land is voided by the father's own sale of the land before his death, and the agency is also voided by the death of either party.