Grand Theft Auto: Liberty City Stories

Either use the raise wanted level cheat or just continue killing cops until you get to 6 stars. That includes taking out the helicopters.

Once you've gotten to Shoreside Vale, get three stars(very easy) then just go on a rooftop or far away from roads with a rocket launcher, and shoot down helicopters until your wanted level gets to 6.

When you get to the third island buy a rocket launcher and a pistol from the gun store that isnt ammunation, the other one get 2 or 3 stars run up the stairs in the gun store shoot all the windows out with a pistol then shoot the cop cars until you get 6 stars

Once you've unlocked Shoreside Vale you can just drive around killing cops until you get 6 stars.