What is the procedure of selling property

Sir/mam my father is three brothers including him and he has one cousin brother.my grandfather was two brothers including him.all of my grand parents are dead.we have lands and one house in ara(Bihar).my both uncles(own) have hired the house for rent and also indirectly sold the house to the renter by taking partial cost of the house without informing my father and without giving us any share.we are under huge debts so only option we had was to sell the land But my uncles (both) are unwilling to sign the official documents which is proof of their consent.in fact they are waiting for us to die out of debts so that they may get surplus advantage of my father's share also.we are in do or die situation and need urgent financial help.we can't afford to hire a lawyer.please guide us what to do. Thanks and regards