The second Alvarez job requires you to create a big, public scene. What better way to do that than with a tank? Take a vehicle of your choice and go pick it up. This is actually a really easy mission - all you need to do, once you're in the tank, is navigate safely to the cathedral, then blast all of the police cars in site until you have achieved a four-star wanted level.
Once that's done, the mission will end - you don't even need to escape from the police.
Reward: 12,000R$