Renaming an association

ActiveRecordAss.rb

class Game < ActiveRecord::Base
  has_and_belongs_to_many :users
  belongs_to :winner, :class_name => "User"
end


class User < ActiveRecord::Base
  has_and_belongs_to_many :games
  validates :name, :uniqueness => true
end

class GamesUser < ActiveRecord::Base
end


class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :name
    end
  end

  
end

class CreateGames < ActiveRecord::Migration
  def change
    create_table :games do |t|
      t.integer :winner_id
      t.timestamps
    end
  end
end

class CreateGamesUsers < ActiveRecord::Migration
  def change
    create_table :games_users do |t|
      t.integer :user_id
      t.integer :game_id
    end
  end
end