My grandfather has extended several loans to people when he was still alive. Those loans are evidenced by written instruments signed by his debtors. Now that my grandfather is gone, his children want to collect from his debtors but most of them claim that they no longer have legal obligation to pay. What should we do to be able to collect from them? What form should my grandfather's heirs make to pass on the responsibility of collecting to only one person among them? Please help me. Thank you and God bless.