Grand Theft Auto: Vice City/Interglobal Films, Inc.

G-Spotlight
You have to use a motorcycle to jump from roof to roof, eventually reaching the spotlight and adjusting it so it would reflect your movie advertisement on a skyscraper. It is difficult because you are prone to fall off the buildings with your bike. If this happens, don't bother to get back from the beginning. Just go to your hideout at Hyman Condo and grab a chopper. It is easier and faster. Remember that this mission always starts at 17:00 and ends at 07:00, so you have limited time.