How do you replace the serpentine belt on 93 VW eurovan?

You have to move the idler pulley that is spring loaded forward to release tension. This pulley is on a short spring loaded shaft at the rear of the pulley group; almost above the shock absorber. vw mechanics have a tool like a lug wrench with a grooved 90 degree end that grabs the shaft. I made one from a bicycle training wheel arm and the bottom of a muffler clamp. this is the only tool needed. take a look and see if you can make a tool or get visegrips on the shaft with a piece of pipe on the visegrip arm .