VOLVO ELECTRIC PARKING BRAKE FAULT, HOW TO RELEASE IN A EMERGENCY XC70 V70 S70 C70 S80 S90 V90 XC90
When the Brake won't release, I show how to retract the motors and what to check to repair or allow the car to be moved.
The method requires a 12volt fused feed, which can be taken from the car battery, or like I used a power pack.
Basically you are connecting a 12v battery across the two pins on the brake calliper.
I used some stiff wires crimped to a couple of terminals, attached to a fused power pack, one direction releases the other applies the pressure.