The benefactors vote to elect a trustee. A town-aligned trustee is allowed to vote on the game winner. A scum-aligned trustee is eliminated. The trustees pick one winner from the Graveyard/Boardroom, the winner's faction also wins.
It's basically a game of lynch the Towniest, because at best you lynch Scum trying to seem Town, at worst you lynch someone that could make derps like Serela worry whether the Towniest isn't a scumploy, and who's probably competent enough to spot the rest of the Townies from beyond the grave.