Ed,
John Muir has a good piece on how to do this in his book (HOW TO KEEP YOUR VOLKSWAGEN ALIVE). Your first have to remove the rear most piece of engine shroud. The nut (30mm) is very tight, so you will probably need a breaker bar to get it loose. You also have to make sure the engine does not turn over, so put in in gear and have your "assistant" hold the brake pedal. If this works, you may be able to tap or pry the pulley off. If not and you want to avoid damaging the pulley (assuming you are not going to replace it) you can buy or rent a puller. You can also make one. John's book goes into some detail how to do this. Basically, it is a bar of flat stock with slots on both ends which align with the holes in the pulley. Bolts and nuts are used to attach the bar to the pulley. Then a bolt is screwed down through a threaded center hole which pushes the pulley off.
That's how it's supposed to work. If you don't have the book, I suggest you purchase it. It's been an invaluable tool for me. Good luck.
John H.
2000 VS