Well, I get guns, like the gun(+5 ammo) from when you enter a Police car, maybe the guns regular police have(have to kill one first or something :0 ) and the one on top of that one safehouse, the one near the police station, a pay & spray, and the hospital(it's in Vice Point)(get more guns and ammo if you like). Then shoot people from the house mentioned before, from the 'balconies'. Shoot policemen as they come, too. It takes a while, but surely soon you can get 5 stars. The gun you get on the house is more useful, even when you can't see the police because of the bushes, because you can shoot their heads off! (Ohmigosh I sound so violent. XD)When you're low on health, run to the nearby hospital to get a heart. It'll respawn if you need it again. If you get stuck, ask. XP
Yeah, it's almost impossible to get the full 6 stars, even with the advice above. I wonder what happens when there's 6 stars... :cer_disbelief: I have a little 1-4 star guide on what happens when you get them, pretty much. =L