In the Rule entitled “Combat”, change the text

If the @ is wielding a weapon, they must roll XDICEY in the GNDT where X is the number of Dice for their weapon, and Y is the number of Sides for their weapon. The result of the die roll (whichever is used), plus the enchantment of whatever weapon the @ wields, minus the AC of any armor worn by whatever the @ is fighting, is the Damage Dealt

to

If the @ is wielding a weapon, they must roll XDICEY in the GNDT where X is the number of Dice for their weapon, and Y is the number of Sides for their weapon. The result of the die roll (whichever is used), plus the enchantment of whatever weapon the @ wields, is the attack’s base damage; they then roll DICEZ, where Z is the total AC of the armors worn by whatever the @ is fighting, and subtract that from the base damage to calculate the damage dealt.

and the text

subtract from that the AC of any armor the @ is wearing and

with

subtract from that the result of a DICEZ roll, where Z is the total AC of the armors the @ is wearing, and