After the cutscene, you have three minutes to use the Dozer to destroy the portables. Watch out for the explosive barrels. After this, you must use the Dozer to push mobile toilet containing the foreman into a hole (besides the pipes), and cover it with concrete.
- If the other Dozer bothers you too much, get off your Dozer and shoot him. The other workers won't use that again. Don't bother killing other workers though as they will keep on spawning.
- Grenades also work nicely in getting rid of the trailers (I also used them to clear out a posse of construction workers before getting down to business).
- You may simply shoot the red explosive barrels, thus easily destroying the portables.
- All schools, except flying school, are unlocked, but only driving school is accessible at this time. After Yay Ka Boom-Boom, bike and boat schools are accessible.