Simply approach your brother or sister and kindly and humbly try to discuss the matter and settle it. Of course, the Bible provides other practical suggestions.
فَبِمَقْدُورِكَ أَنْ تَذْهَبَ إِلَى أَخِيكَ وَتَحُلَّ مَعَهُ ٱلْمَسْأَلَةَ بِلُطْفٍ وَتَوَاضُعٍ .‏