Well, Gellak the Half-Orc Bard kind of inherited the sword after his friend, Durrash, killed the previous owner and then inconvenient-like got himself killed defending us from a dragon.
The thing is this: Gellak is a good bloke, and knows that the sword is neutral evil and (at least in our version of this world) is determined to kill neutral good beings. Now, Gellak can't go along with that -- he's chaotic good.
His first thought was to destroy it using Dispel Magic: this would, with a good enough roll, would seem to provide a means to eliminate the evil weapon, preventing it from doing its dastardly deeds via Gellak or anyone else.
However, the best move, considering the rarity of such powerful items would be to find a way to change the alignment of the sword.
Yes, this will probably turn into a quest, but the DM sent me to the Waterdeep Archives and libraries looking for answers, giving me a chance to come up with a plausible solution.
What are the known (or logical) ways to change the alignment of a legendary item in a 5e campaign? Who would be the people in Waterdeep that might have answers to this question if you, Oh Wise Sages, do not?