here i think this myght help you out
*Demolition Man*
Difficulty: 5/10
This is a pretty challenging mission, because the helicopter controls are
wacky. You may want to do a test mission just to learn how to fly it.
Head up the street to the Top Fun van, and grab a bomb. Fly to the
construction site and drop it in the pink area. Try not to get hit by the
workers' hammers, as they will eventually destroy you. You have to go up
the stairs for the next ones, you cannot fly around through windows.
Repeat the process for the first one trying not to get shot down or
hammered. The time limit is very gracious, so ignore it. It just tries
to scare you. After you've done this, enjoy the fireworks.
Sasha Gajic also says: "Your helicopter is a mean, lean, construction
worker slicing machine…if you’re getting nervous about all the hammer
swinging workers, get ahead of them a bit, lower yourself close to the
ground, and fly back into them. Instant salad, and no pressure!"
Reward: $1000