If you havnt got the software to depressurise the system there is another way. put car on ramp with susppension on low and cap removed and disconect the battery. next to the rear height adjuster youul see a bleed nipple with the suspension pipes connected to it. put a hose over the nipple and open it very slowly and just a bit at a time so you can control the flow. Once the plow has stopped the system has lost its pressure