1995 Volkswagen Eurovan Belt replacement

The rear most pulley has the tensioner built into it. You'll need a 16-19mm (changes over the years) open end wrench to put on the square nub mounted on it. Once you get the wrench on it, turn it clockwise adn that will loosen the tension.

Without the factory tool it can be a little difficult and may require a second set of hands to remove the belt while you loosen the tension.