Bloody Hard Difficulty  -  Complete story mode once, by taking over the whole city, with any gang.
Bloody Hard Difficulty Complete Story Mode

Free Roam  -  Unlock characters and cars for free drive mode, by taking over these gangs headquarters in story mode.

Andy Steele Car Take over the Steele gang HQ
Andy Steele Character Take over the Steele gang HQ
Asif Rashid Character Take over the Talwar Brothers HQ

EC2 Crew Car Take over the EC2 Crew HQ

Mason Grant Character Take over the EC2 Crew HQ
Morris Kane Car Take over the Kane Firm HQ
Morris Kane Character Take over the Kane FirmHQ

Shan Chu Yang Character Take over the Water Dragon Triad HQ

Talwar Car Take over the Talwar Brothers HQ

Yang Car Take over the Water Dragon Triad HQ

Zakharov Car Take over the Zakharov Organisation HQ
Zakharov Character Take over the Zakharov Organisation HQ

Gang bosses  -  Here is how to unlock each boss from the various gangs.

Andy Steele kill him in story mode
Asif Rashid finish Talwar bros tutorial

Mason Grant finish Ec2 Crew tutorial
Morris Kane finish Morris Kane firm tutorial

Shan Chu Yang finish the Water Dragon's tutorial

Zakharov finish Zakarov's tutorial