You cannot see through the window it is a wall that you can walk through that has a window design on it. Once there, you should see that a part of the helipad touches the neighboring building. You can walk into the arrow and you will be on top of the VCN building.
If you are coming directly from the Ammu-Nation, it should be on your left. Go to the bridge that leads to Prawn Island from the east side of Vice City. This time it is literally under construction. There is an "Easter Egg" from Grand Theft Auto: Vice City that is in Vice City Stories, and it is in the exact same location. Do not press it all the way or you will stand up, which makes you go slower. You can reach maximum speed on scooters and motorcycles by pressing Up slightly on the Analog-pad to duck your head. Make sure to hit the doors off of the back this should make it easier. | Submitted by GrantandAlex The person should get out and it should count as a rescue. While doing the Ambulance Rescue, when you go to pick up a person,(usually works in the back doors) right before they are about to get in, get out of the ambulance and get right back in. Watch mission cutscenes at Clymenus Suite - 100% Completion