Father selling grandfather property due to drinking habit

MY FATHER SELLING THE GRANDFATHER PROPERTY TO FOR DRINKING MONEY WHEN REQUESTED TO TRANSFER PROPERTY TO THEIR DOUGHTER AND SON. HE TELLING HE CAN JUST MAKE A WILL BUT DO NOT TRANSFER THE PROPERTY. BOTH CHILD IS UNMARRIED AND UNEMPLOYED. FATHER EARN NOTHING IN HIS LIFE GRANDFATHER PROPERTY SELLING TO SATISFY DRINKING HABIT. NOT BOTHER FOR THE DAUGHTER MARRIAGE AND ALL WHAT CAN THE BOTH CHILD DO TO STOP THE SELLING OF PROPERTY OR TRANSFER OF PROPERTY.