What is the ruling of Islamic law concerning disputes over a father's will to divide apartments among his daughters, and is it permissible for the sisters to waive their right in the will?

When a person dies, their body is prepared and shrouded, then their debts are paid, and then their will is executed for non-heirs, provided it does not exceed one-third of the estate. As for a bequest to an heir, the heirs are not obligated to execute it unless they agree to it. The will that must be executed is that which is for a non-heir and within the limit of one-third. An adult, sane heir may relinquish their share of the estate to another.