The parking entrance isn't very visible from the street. You have to turn into the curved driveway in front of the building. It doesn't look like it, but there's an opening that leads into the underground parking lot. Look for the signs directing you to the "Tower" elevators.
When you exit the elevator, take the doors to your right to enter the "Tower" building. Go down the hall then make your first right. Otherwise, you can enter through the front of the building. If so, the place is on your left as soon as you enter. Oh, don't forget to bring your parking ticket to get it validated at the shop.
The rates are pretty reasonable here. Stopped in, told them what I wanted, filled out a short form, and receive my currency. Straight forward and simple. Cash only.