Instructions
Walk to the Entrance Plaza area. This is the location where Frank was when the game first started. Climb the broken escalator to the second floor.
Enter the fancy "Modern Businessman" men's clothing store by either using the front door or kicking in the glass display windows. This store is located at the top of the escalator.
Select the racks of clothes in the store to put on the white business suit. This stylish suit also comes with a striped tie.