To take over a compound, equip all of your guns with ammunition, or use a powerful gun to kill other gangsters and take their gun. You should have cover at all times. Note: When behind the bushes to the left of the entrance they can shoot you through the bushes. Once inside, do the same thing and always have cover. Then, run downstairs. In the back house there are two men. One is behind a box and there is another behind a pillar. After those two are dead, set the time bomb (not dynamite). If needed, stay in the basement and die, then drive back and repeat on the other house.
When you are ready to take over a compound, the Tattaglias in northeast Brooklyn is recommended because they may be the weakest family in New York, but that does not mean they are going to be very simple to defeat either. Bring some bombs along and blow up the support pillars in the basements. You may start a mob war, but if you are successful you will have a new safe house with a group of guards.