It is not designed with pedestrians in mind as such: afaik there is no pedestrian path as such to exit the car park; you would just walk along the road the cars use for exit ( with no pavement but would not be particularly dangerous, at any rate if it is not dark) and the road you need to cross (Ring Road South) has no zebra crossing but it should be pretty straightforward and less than 5 minutes walk from the entrance of the long stay car park to the Hilton. That said, the car park shuttles are frequent and will drop you just a very short walk from the Hilton anyway so that would probably work just as well. If there was a shuttle about to depart shortly, I would just take the shuttle. If there is no sign of a shuttle departing shortly and you are not parked too far from the exit of the car park, I would consider walking.