How do you adjust the headlight beam located on a 1993 Buick Park Avenue?

I had my 92 park avenue in the shop and asked them to adjust the headlights. They told me they couldn't because you have to have a special tool to be able to do so, and I would have to go to a dealer to get them adjusted. I've been on the web looking to see if I can buy one, but so far, no such luck.