Start point: The attacker is grabbing her victim from the back.
Victim positions her foot in the direction she plans to hook her leg on the attacker.
Victim lifts and hooks one of her legs onto the attacker's in order to make her unbalanced.
Victim must pull the attacker's arm away her body.
Victim uses her elbow to hurt her attacker.
Victim stabilizes herself and uses her knee to hit her attacker.
In order to escape the attacker, the victim pries the attacker's fingers off of the hand that is keeping her in hold.
DO NOT pull on the free hand because it's not effective.