Hi, i have a v, astra hatch, 2.0 cdti sri 2011 with etb parking brake. I need to replace the rear pads and rewind the calipers. I know the epb can be released without computer, by pressing brake and switch.? Having tried no flashing lights appear with what I've been told. Can someone please advise me on how to put into service mode so I can change pads please. Thank you.