If one sees gross injustice or bias on the part of a testator, and takes corrective action to restore justice to the will, he commits no sin. God is Forgiver, Most Merciful.
فَمَن خافَ مِن موصٍ جَنَفًا أَو إِثمًا فَأَصلَحَ بَينَهُم فَلا إِثمَ عَلَيهِ إِنَّ اللَّهَ غَفورٌ رَحيمٌ
faman khaafa mim moosin janafan aw isman fa aslaha bainahum falaaa ismaa ‘alayh; innal laaha Ghafoorur Raheem