Combine all the ingredients in bowl and give it a stir.
Pour mix into a large double bagged freezer bag. Freeze overnight. The alcohol in the mix will prevent the juice from freezing solid. It should just get nice and slushy.
Store deep down in your cooler to prolong the slushiness. If it does melt, enjoy it on the rocks instead.
To serve, rub a lime wedge around the rim of a cup, rim it with salt and pour/scoop some margarita into the cup.