(Al-Baqara) 2 : 182
فَمَنْ خَافَ مِنْ مُوصٍ جَنَفًا أَوْ إِثْمًا فَأَصْلَحَ بَيْنَهُمْ فَلَا إِثْمَ عَلَيْهِ ۚ إِنَّ اللَّهَ غَفُورٌ رَحِيمٌ
Then, anyone who fears discrimination in the part of the bequest or sin, there is no blame upon him in making reconciliation among them; indeed, Lord Allah is the Forgiving, the Merciful.
If the dead man had made the bequest against the do’s and don’ts of Adhikr, then there is no blame to change the bequest according to the Book. There is no blame to improve the bequests according to the dos and don’ts of Adhikr. See explanation 4: 135; 5: 8, 44, 45, and 47.